A look at House candidates in Orange County, California

The Democratic drive to take control of the U.S. House in November might rise or fall on the California coast. As part of its strategy, the party is targeting four Republican-held seats in Orange County, southeast of Los Angeles, which Hillary Clinton carried in the 2016 presidential election.

Meanwhile, the county, a one-time Republican stronghold, has gradually grown more diverse and Democratic in its politics. Here's a look at candidates in the four districts in play:

39TH CONGRESSIONAL DISTRICT

FILE - In this Jan. 10, 2012, file photo, California Assemblywoman Diane Harkey, R-Dana Point, is seen during a Capitol news conference in Sacramento, Calif. Harkey, a Republican candidate for a U.S. House seat in the 49th Congressional District, has been endorsed by Trump. For decades, Orange County, California, was known as a Republican stronghold, but it has gradually grown more diverse and Democratic in its politics. (AP PhotoRich Pedroncelli, File)

It includes parts of Orange, Los Angeles and San Bernardino counties.

— Young Kim, Republican. The 55-year-old South Korean immigrant and former state lawmaker worked for retiring Rep. Ed Royce for years and is well-known in the district, where registration is closely divided. She's running as a supporter of President Donald Trump with an independent streak. She says she opposes increased trade tariffs imposed by the administration. Kim was born in South Korea and grew up in Guam before coming to the U.S.

— Gil Cisneros, Democrat. The 47-year-old Navy veteran and former Frito-Lay manager is a first-time candidate arguing for change in gridlocked Washington. The son of a public school cafeteria worker and a Vietnam veteran, Cisneros and his wife won a $266 million lottery jackpot and run a charitable foundation. He says he wants to continue in public service and that voters are often surprised that someone with his wealth would want to get involved in the nasty partisan battles on Capitol Hill.

FILE - In this Sept. 8, 2018, file photo, Mike Levin, a Democratic candidate in the 49th Congressional District, attends the Take It Back California event where former President Barack Obama campaigns in support of California congressional candidates in Anaheim, Calif. Southern California's Orange County was known as a Republican stronghold for decades. Democrats this year hope to capture as many as four Republican-held U.S. House districts in the county. (AP PhotoRingo H.W. Chiu, File)

45TH CONGRESSIONAL DISTRICT

Entirely in Orange County.

— Rep. Mimi Walters, Republican. She was re-elected two years ago by a 17-point margin in a district where Republicans have a shrinking registration edge. Walters, 56, has been promoting the region's economic growth under Trump's stewardship. The former investment banker and state lawmaker supported the president on the federal tax overhaul and Republicans' attempts to repeal former President Barack Obama's health care law.

FILE - In this Aug. 31, 2012, file photo, state Sen. Mimi Walters, R-Lake Forest, speaks at the Capitol in Sacramento, Calif. Rep. Walters is a candidate running for a U.S. House seat against Democrat Katie Porter in the 45th Congressional District. For decades, Orange County, California, was known as a Republican stronghold but times have changed. Now, Hispanics and Asians together are the majority and more voters are registering as Democrats and independents. (AP PhotoRich Pedroncelli, File)

— Katie Porter, Democrat. The 44-year-old law professor was appointed by former state Attorney General Kamala Harris to oversee California's share of a $25 billion national mortgage settlement following the housing crisis. She's a protege of Sen. Elizabeth Warren, the Massachusetts Democrat who's a favorite of the party's liberal wing. Porter wants to overturn Trump's tax plan and she supports universal health care.

48TH CONGRESSIONAL DISTRICT

Entirely in Orange County.

FILE - In this June 5, 2018, file photo, Harley Rouda, a Democratic candidate for Congress in the 48th District in Orange County, poses during interviews in Newport Beach, Calif. The Republican-turned-Democrat says he’s not a politician but is tired of Washington representatives failing to meet the needs of the people they serve. For decades, Orange County, California, was known as a Republican stronghold, but it has gradually grown more diverse and Democratic in its politics. (AP PhotoKrysta Fauria, File)

— Rep. Dana Rohrabacher, Republican. The congressman was easily re-elected two years ago, but Democrats see an opportunity to oust a long-serving member whose name has come up in the investigation into Russian meddling in the 2016 election. He has denied any wrongdoing. Rohrabacher, 71, is a one-time cold warrior who became Russia's leading defender on Capitol Hill. The guitar-strumming congressman who loves to surf is a former speechwriter for President Ronald Reagan and is known for his longtime support for legalized marijuana and skepticism about climate change.

— Harley Rouda, Democrat. The businessman, real estate developer and lawyer is making his first run for the House. The Republican-turned-Democrat says he's not a politician but is tired of Washington representatives failing to meet the needs of the people they serve. His ads depict him as a Democrat in the mold of Obama. "We need new leadership that trusts science, acts on climate change, demands that polluters clean up their mess," Rouda, 56, says on his website.

49TH CONGRESSIONAL DISTRICT

FILE - In this Monday, Oct. 1, 2018, file photo, Young Kim, speaks at a gas tax rally in Fullerton, Calif. In the 39th Congressional District, Kim, a Korean immigrant Republican is running for a U.S. House seat against Gil Cisneros, a Hispanic Democrat. Kim is trying to become the first Korean-American woman elected to Congress. (AP PhotoChris Carlson, File)

It includes parts of San Diego and Orange counties.

— Diane Harkey, Republican. Nine-term Republican Rep. Darrell Issa is stepping aside after surviving his 2016 race by 1,600 votes, a confirmation that the once solidly Republican district has grown more Democratic. Harkey, a former state lawmaker who sits on a state tax board and earlier worked in corporate finance and banking, has been endorsed by Trump. The president's campaign recently tweeted that she would be a "great supporter" of Trump's agenda. Harkey, 67, has called her Democratic rival out of step with the district and warned of higher taxes, runaway regulations and government-run health care with Democrats in charge.

— Mike Levin, Democrat. The environmental attorney has sparred with Harkey over Trump's agenda, global warming and immigration. "Sorry, President Trump, but climate change is real," he says in an online video. Levin, who turns 40 on Saturday, has called Harkey a "rubber stamp" for the White House. On his website, he says he will not be a rigid partisan in Washington but wants to build coalitions to improve the environment and establish universal health care.

FILE - In this Aug. 21, 2018, file photo, Katie Porter, a Democratic candidate seeking election to the U.S. House to represent the 45th Congressional District of California poses in Laguna Beach, Calif. Porter is running against Republican Rep. Mimi Walters. Democrats this year hope to capture as many as four Republican-held U.S. House seats in the county. (AP PhotoChris Carlson, File)

FILE - In this Sept. 8, 2018, file photo, Democratic congressional candidate, Gil Cisneros, attends the Take It Back California event where former President Barack Obama campaigns in support of California congressional candidates in Anaheim, Calif. Cisneros, a Hispanic Democrat, is running against Young Kim, a Republican who is a Korean immigrant. Democrats this year hope to capture as many as four Republican-held U.S. House seats in the county. (AP PhotoRingo H.W. Chiu, File)

TOKYO (AP) — The American envoy to the United Nations called Friday for countries armed with atomic weapons to pursue nuclear disarmament as she visited the atomic bomb museum in Nagasaki, Japan.

Linda Thomas-Greenfield, who became the first U.S. cabinet member to visit Nagasaki, stressed the importance of dialogue and diplomacy amid a growing nuclear threat in the region.

“We must continue to work together to create an environment for nuclear disarmament. We must continue to prevent the spread of nuclear weapons in every corner of the world,” she said after a tour of the atomic bomb museum.

“For those of us who already have those weapons, we must pursue arms control. We can and must work to ensure that Nagasaki is the last place to ever experience the horror of nuclear weapons,” she added, standing in front of colorful hanging origami cranes, a symbol of peace.

The United States dropped the world’s first atomic bomb on Hiroshima on Aug. 6, 1945, destroying the city and killing 140,000 people. A second attack three days later on Nagasaki killed 70,000 more people. Japan surrendered on Aug. 15, ending World War II and its nearly half-century of aggression in Asia.

Nagasaki Gov. Kengo Oishi said in a statement that he believed Thomas-Greenfield's visit and her first-person experience at the museum “will be a strong message in promoting momentum of nuclear disarmament for the international society at a time the world faces a severe environment surrounding atomic weapons.”

Oishi said he conveyed to the ambassador the increasingly important role of Nagasaki and Hiroshima in emphasizing the need of nuclear disarmament.

Thomas-Greenfield's visit to Japan comes on the heels of Prime Minister Fumio Kishida's official visit to the United States last week and is aimed at deepening Washington's trilateral ties with Tokyo and Seoul. During her visit to South Korea earlier this week, she held talks with South Korean officials, met with defectors from North Korea and visited the demilitarized zone.

The ambassador said the United States is looking into setting up a new mechanism for monitoring North Korea's nuclear weapons program. Russia and China have thwarted U.S.-led efforts to step up U.N. sanctions on North Korea over its ballistic missile testing since 2022, underscoring a deepening divide between permanent Security Council members over Russia’s war on Ukraine.

She said it would be “optimal” to launch the new system next month, though it is uncertain if that is possible.

The U.N. Security Council established a committee to monitor sanctions, and the mandate for its panel of experts to investigate violations had been renewed for 14 years until last month, when Russia vetoed another renewal.

In its most recent report, the panel of experts said it is investigating 58 suspected North Korean cyberattacks between 2017 and 2023 valued at approximately $3 billion, with the money reportedly being used to help fund its weapons development.

The United States, Japan and South Korea have been deepening security ties amid growing tension in the region from North Korea and China.

U.S. Ambassador to United Nations Linda Thomas-Greenfield, left, and Japan's Prime Minister Fumio Kishida, right, shake hands during a meeting Friday, April 19, 2024, at prime minister's office in Tokyo. (AP Photo/Eugene Hoshiko, Pool)

U.S. Ambassador to United Nations Linda Thomas-Greenfield, left, and Japan's Prime Minister Fumio Kishida, right, shake hands during a meeting Friday, April 19, 2024, at prime minister's office in Tokyo. (AP Photo/Eugene Hoshiko, Pool)

U.S. Ambassador to United Nations Linda Thomas-Greenfield, right, speaks to Rahm Emanuel, U.S. Ambassador to Japan, second right, as they wait for a meeting with Japan's Prime Minister Fumio Kishida Friday, April 19, 2024, at prime minister's office in Tokyo. (AP Photo/Eugene Hoshiko, Pool)

U.S. Ambassador to United Nations Linda Thomas-Greenfield, left, and Rahm Emanuel, U.S. Ambassador to Japan, right, walk to meet Japan's Prime Minister Fumio Kishida Friday, April 19, 2024, at prime minister's office in Tokyo. (AP Photo/Eugene Hoshiko, Pool)

U.S. Ambassador to United Nations Linda Thomas-Greenfield, left, and Japan's Prime Minister Fumio Kishida, right, talk prior to a meeting Friday, April 19, 2024, at prime minister's office in Tokyo. (AP Photo/Eugene Hoshiko, Pool)

U.S. Ambassador to United Nations Linda Thomas-Greenfield, left, and Japan's Prime Minister Fumio Kishida, right, prepare to talk during a meeting Friday, April 19, 2024, at prime minister's office in Tokyo. (AP Photo/Eugene Hoshiko, Pool)