President Biden has proposed a five-year extension with Russia to the only remaining nuclear treaty between the two countries, before it expires on February 5. The New Strategic Arms Reduction Treaty, or New START, limits the number of deployed strategic nuclear warheads to 1,550 each. This is White House Press Secretary Jen Psaki.

Press Secretary Jen Psaki: “The New START treaty is in the national security interests of the United States. And this extension makes even more sense when the relationship with Russia is adversarial, as it is at this time.”

This comes as the Treaty on the Prohibition of Nuclear Weapons goes into effect today. The U.N.-backed agreement was ratified by 51 countries, but those do not include any of the world’s nine nuclear powers — Britain, China, France, India, Israel, North Korea, Pakistan, Russia and the United States.