Israel's prime minister on Sunday stepped up his calls for world powers to end the 2015 nuclear deal with Iran as President Donald Trump decides whether to withdraw from the agreement by next week.

Israeli Prime Minister Benjamin Netanyahu chairs the weekly cabinet meeting in Jerusalem, Sunday, May 6, 2018. Netanyahu said Sunday that Iran is supplying advanced weapons to Syria that pose a danger to Israel and that it's better to confront Tehran sooner rather than later. (Jim Hollander/Pool Photo via AP)

Israeli Prime Minister Benjamin Netanyahu chairs the weekly cabinet meeting in Jerusalem, Sunday, May 6, 2018. Netanyahu said Sunday that Iran is supplying advanced weapons to Syria that pose a danger to Israel and that it's better to confront Tehran sooner rather than later. (Jim Hollander/Pool Photo via AP)

In a briefing to foreign reporters, Benjamin Netanyahu said the world would be better off without any deal than with what he called the "fatally flawed" agreement reached in 2015.

Netanyahu said Israel is sharing a trove of confiscated Iranian nuclear documents with the six world powers that signed the deal, as well as other countries, in hopes of mounting further opposition to the deal. He heads to Moscow later this week for a meeting with President Vladimir Putin, where talks will focus on the Iranian nuclear program and Iran's involvement in neighboring Syria.

FILE - In this Monday, April 30, 2018, file photo, Israeli Prime Minister Benjamin Netanyahu presents material on Iran’s purported nuclear program in Tel Aviv. (AP Photo/Sebastian Scheiner, File)

FILE - In this Monday, April 30, 2018, file photo, Israeli Prime Minister Benjamin Netanyahu presents material on Iran’s purported nuclear program in Tel Aviv. (AP Photo/Sebastian Scheiner, File)

"I said it from the start, it has to be either fully fixed or fully nixed," Netanyahu said. "But if you do nothing to this deal, if you keep it as is, you will end up with Iran with a nuclear arsenal in a very short time."

Netanyahu was a vocal opponent of the deal when it was reached during the Obama administration. The agreement lifted painful economic sanctions against Iran in exchange for curbs on its nuclear program.

FILE-Israeli Prime Minister Benjamin Netanyahu presents material on Iranian nuclear weapons development during a press conference in Tel Aviv, Monday, April 30, 2018. (AP Photo/Sebastian Scheiner)

FILE-Israeli Prime Minister Benjamin Netanyahu presents material on Iranian nuclear weapons development during a press conference in Tel Aviv, Monday, April 30, 2018. (AP Photo/Sebastian Scheiner)

Netanyahu has repeatedly argued that the deal will not prevent Iran from gaining nuclear weapons capability after its restrictions expire in the next decade or so. Trump has voiced similar objections and hinted he will withdraw from the deal unless it is renegotiated.

Netanyahu did not accuse Iran of violating the deal. Instead, he said the deal, reached by the Obama administration, was so weak that Iran has no need to break it. He said the flaws include permission for Iran to continue some low-level enrichment of uranium and its continued development of long-range missiles capable of delivering a bomb. He said the nuclear documents unveiled by Israel last week prove that Iran also pursued the know-how on how to develop and detonate a bomb.

"I say that a deal that enables Iran to keep and hide all its nuclear weapons know-how, is a horrible deal," he said.

Netanyahu last week showed off what he said was an "a half ton" of Iranian nuclear documents dating back to 2003.

A senior Israeli intelligence official said there were over 100,000 pages of documents that gave Israel new insight into how far the Iranian nuclear program progressed. The official, speaking on condition of anonymity under briefing guidelines, said the volume of information showed the program was more "comprehensive and robust" than previously thought.

Trump's criticism of the deal has given Netanyahu a rare chance to reopen negotiations that appeared to have concluded in 2015. So far, Europe, China, and Russia have shown no interest in revisiting the topic.

European countries, which have been pressing Trump to stick with the deal, have said Netanyahu's presentation only reinforced the importance of the agreement, which provides for inspections.

It remains unclear what would happen if the U.S. withdraws from the deal but the other countries remain committed.

Netanyahu appears to be betting that the pressure of renewed American sanctions could be enough to persuade companies to stop doing business with Iran. He also seems to be hopeful that the threat of military action, either U.S. or Israeli, will deter Iran from resuming its nuclear activities.

Yoel Guzansky, an analyst at the Institute for National Security Studies, an Israeli think tank, said Trump is playing "a game of chicken" with Iran in hopes of renegotiating a better deal.

"They hope that by threatening to walk away from the deal they might get that. I am not so sure, not so sure, the Europeans are not on board, of course, the Russians and the Chinese are not on board," he said. Walking away, he added, could have hard-to-predict consequences.

Israel considers Iran its arch-enemy, citing Iran's calls for Israel's destruction, support for militant groups across the region and growing military activity in neighboring Syria. Israel has warned that it will not allow Iran, whose troops are backing Syrian President Bashar Assad, to establish a permanent military presence in Syria.

Israel is believed to have been behind recent airstrikes on Syrian military bases that killed Iranian soldiers, prompting Tehran to vow retaliation. Israel has neither confirmed nor denied involvement.

The possibility of the nuclear deal collapsing has raised concerns it might embolden Iran to strike Israeli targets.

Netanyahu told his Cabinet earlier Sunday that Iran has delivered advanced weapons to Syria "in order to attack us both on the battlefield and on the home front."

"We are determined to block Iran's aggression against us even if this means a struggle. Better now than later," he said. "We do not want escalation, but we are prepared for any scenario."