U.S. Secretary of State Mike Pompeo and Russian Foreign Minister Sergey Lavrov discussed arms control and other issues Friday as Moscow has signaled readiness to include some of its latest nuclear weapons in the last remaining arms control pact between the two countries if Washington accepts the Kremlin's offer to extend it.

The State Department said the two top diplomats discussed the next steps in the bilateral strategic security dialogue. Pompeo emphasized that any future arms control talks must be based on U.S. President Donald Trump’s vision for a trilateral arms control agreement that includes China along with the U.S. and Russia, the State Department said.

Russian President Vladimir Putin has offered to extend the New START arms control treaty that expires in February 2021. The Trump administration has pushed for a new pact that would include China as a signatory. Moscow has described that goal as unrealistic given Beijing's reluctance to discuss any deal that would reduce its much smaller nuclear arsenal.

FILE - In this undated video grab provided released by the Russian Defense Ministry, a Russian Poseidon nuclear-powered underwater drone is photographed being test-launched, in Russia. Russian Deputy Foreign Minister Sergei Ryabkov said that the Poseidon doesn't fall under the New START arms control treaty with the United States, but added that Moscow is ready to discuss it as part of broader talks with Washington on strategic stability. (Russian Defense Ministry Press Service via AP, File)

FILE - In this undated video grab provided released by the Russian Defense Ministry, a Russian Poseidon nuclear-powered underwater drone is photographed being test-launched, in Russia. Russian Deputy Foreign Minister Sergei Ryabkov said that the Poseidon doesn't fall under the New START arms control treaty with the United States, but added that Moscow is ready to discuss it as part of broader talks with Washington on strategic stability. (Russian Defense Ministry Press Service via AP, File)

During Friday's call with Pompeo, Lavrov reiterated Moscow's offer to extend New START, saying that Russia is ready to discuss possible new agreements but considers it important to preserve the existing treaty as a “cornerstone of global security,” the Russian Foreign Ministry said. It added that the top diplomats agreed to intensify the U.S.-Russian arms control dialogue.

Deputy Foreign Minister Sergei Ryabkov said Friday that Russia's new Sarmat heavy intercontinental ballistic missile and the Avangard hypersonic glide vehicle could be counted along with other Russian nuclear weapons under the treaty.

The Sarmat is still under development, while the first missile unit armed with the Avangard became operational in December.

The Russian military has said the Avangard is capable of flying 27 times faster than the speed of sound and could make sharp maneuvers on its way to a target to bypass missile defense systems. It has been fitted to the existing Soviet-built intercontinental ballistic missiles instead of older type warheads, and in the future could be fitted to the more powerful Sarmat.

The New START Treaty, signed in 2010 by U.S. President Barack Obama and Russian President Dmitry Medvedev, limits each country to no more than 1,550 deployed nuclear warheads and 700 deployed missiles and bombers.

The treaty, which can be extended by another five years, envisages a comprehensive verification mechanism to check compliance, including on-site inspections of each side’s nuclear bases.

New START is the only U.S.-Russia arms control pact still in effect. Arms control experts have warned that its demise could trigger a new arms race and upset strategic stability.

Ryabkov said in an interview with the Mezhdunarodnaya Zhizn magazine that other prospective weapons announced by Putin in 2018 don’t fall under the pact’s provisions, but Russia is open for discussion on their possible inclusion as part of a wider dialogue about strategic stability.

Those weapons include the Burevestnik nuclear-powered cruise missile and the atomic-powered and nuclear-armed Poseidon underwater drone described as capable of creating a tsunami to slam an enemy coastline.

Russia has cast the development of Avangard, Burevestnik and Poseidon as a response to U.S. missile defense, which it called a threat to its nuclear deterrent. It also has voiced concern about U.S. plans to deploy weapons in space.