Updated

Britain's defense secretary says the U.K. stands "absolutely resolute" with the United States as President Donald Trump announced he will pull out from a landmark arms control agreement with Russia.

Gavin Williamson blamed Russia for endangering the arm control pact, agreed between the U.S. and the Soviet Union in 1987, and called on the Kremlin to "get its house in order."

Trump said he will exit the pact because Russia has violated it "for many years" and it's preventing the U.S. from developing new weapons.

Backing Trump, Williamson told the Financial Times on Sunday that Moscow had made a "mockery" of the Intermediate-Range Nuclear Forces Treaty.

The 1987 pact prohibits the United States and Russia from possessing, producing or test-flying a ground-launched cruise missile with a range of 300 to 3,400 miles.