Experts warn that the expiration of a long-standing nuclear arms control treaty between the two superpowers could mark the start of a new nuclear rivalry.

A Russian official said Moscow is ready to respond with military measures if the United States deploys its missile defense program to Greenland.

The agreement was reached following meetings between U.S. Gen. Alexus Grynkewich, who is the commander in Europe of both U.S. and NATO forces, and senior Russian and Ukrainian military officials, the U.

At least two people were killed by a Russian drone strike on Ukraine’s Dnipropetrovsk region on Wednesday, just hours before negotiators from Kyiv, Moscow and the United States are due to enter peace talks in Abu Dhabi.

Hosted by Abu Dhabi, representatives from Russia, Ukraine and the United States sat down for talks on ending the war in Ukraine for the first time.

China has firmly rejected U.S. calls to join nuclear arms control talks with Russia, particularly following the recent expiration of the New START treaty. This development leaves the U.S. and Russia without binding limits on their nuclear arsenals for the first time in decades.

China urged the U.S. to quickly work with Russia on a solution to manage their nuclear arsenals now that the New START arms control treaty has expired. New START was the last remaining nuclear arms pact between Russia and the U.