MOSCOW (REUTERS) - Russia denied on Friday (May 22) a US accusation that it had repeatedly violated the Open Skies treaty, which allows unarmed surveillance flights over member countries, and said it was Washington that had flouted the terms of the pact.

Washington said on Thursday it would pull out of the 35-nation treaty within six months, the Trump administration's latest move to withdraw from a major global accord.

Russia's Deputy Foreign Minister Sergei Ryabkov said Washington had not cited any facts to back up its accusation.

He described what he said were US violations of the treaty as "flagrant" and promised to provide detailed evidence of them to other signatory nations.

"We will spend more time having dialogue with these countries to show... with slides, with booklets, why the United States is lying in its claim that Russia is violating the Open Skies treaty, why the US itself is violating this treaty, and what way forward Russia is offering," Ryabkov said.

The disagreement between the two nuclear powers sours the atmosphere at a time when Washington is considering whether to agree to extend the 2010 New START accord, which imposes the last remaining limits on US and Russian deployments of strategic nuclear arms.

The New START treaty expires in February.

Ryabkov said Washington's proposed withdrawal from the Open Skies treaty mirrored the US decision to pull out of the Intermediate-range Nuclear Forces Treaty with Russia in August 2019.

"The collapse of that agreement, in many ways key to strategic stability, was another phase in the Americans' dismantling of the international security architecture," said Ryabkov.

His colleague, Deputy Foreign Minister Alexander Grushko, earlier said Russia intends to fully comply with all its obligations under the Open Skies treaty despite the US move.