"Our close and long-term ally, of course, is the United States, and we will be absolutely resolute with the United States in hammering home a clear message that Russia needs to respect the [INF] Treaty obligation that it signed," Williamson told Financial Times.
At the same time, Williamson stressed that the UK would like to see "this treaty continue to stand."
"But it does require two parties to be committed to it and at the moment you have one party that is ignoring it. It is Russia that is in breach and it is Russia that needs to get its house in order," Williamson said, blaming Moscow for making a "mockery" of the INF Treaty.
His remarks came as Russian Deputy Foreign Minister Sergei Ryabkov said that Moscow is alarmed by Trump's intention to withdraw from the INF Treaty, which he characterized as US "blackmailing attempts."
Ryabkov said that the US accusations toward Russia regarding the document seem to be aimed at concealing its own violations of the treaty. He added that the US has no reason to say that Russia is violating the INF treaty, and that all of the accusations were unsubstantiated.
Ryabkov warned that if the US continues to withdraw unilaterally from its agreements, then Russia will adopt a range of retaliatory measures, including military ones.
The New York Times reported on Friday that the US plans to withdraw from the INF Treaty next week due to Russia's alleged violations of the document, and that national security adviser John Bolton will notify Russia about the move during his upcoming visit to Moscow.
Over the past few years, Russia and the US have repeatedly accused each other of violating the treaty, which was signed by the USSR and the US back in 1987.
The document stipulates the elimination of nuclear and conventional missiles and their launchers with ranges of 500–1,000 kilometers (310–620 miles) and 1,000–5,500 kilometers (620–3,420 miles).
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