Russia condemned the U.S. on Sunday for announcing that it intended to pull out of a Reagan-era nuclear arms control treaty, terming the Trump administration's move as "blackmail" to get other concessions from the country.

"We condemn the continuing attempts to achieve Russia’s concessions through blackmail, moreover in such an issue that has importance for international security and security in the nuclear weapons sphere [and] for maintaining strategic stability,” Russian Deputy Foreign Minister Sergei Ryabkov told the official news agency TASS.

Ryabkov added: “Unlike our American colleagues, we understand all the seriousness of the issue and its significance for security and strategic stability.”

President Trump said Saturday that he would pull the U.S. out of the 1987 Intermediate-Range Nuclear Forces Treaty which covers land-based, mid-range missiles. The administration alleges that Russia has been violating the terms of the treaty by developing new cruise missiles.

United Kingdom Defense Secretary Gavin Williamson said Saturday that his country would back the U.S. on the matter. "We will be absolutely resolute with the United States in hammering home a clear message that Russia needs to respect the treaty obligation that it signed," he said.