A senior Russian diplomat has made comments at a disarmament conference to justify the suspension of his country's participation in the New START nuclear arms control treaty it signed with the US. Western delegates left the meeting in protest as he made the remarks.

Russian Deputy Foreign Minister Sergey Ryabkov was speaking on Thursday in Geneva at the UN Conference on Disarmament.

Ryabkov said the greatest threat is posed by the US and NATO aimed at further fomenting the conflict in and around Ukraine.

He said the situation surrounding the treaty has further escalated following US attempts to probe the security of Russian strategic facilities declared under the treaty by helping Ukraine carry out armed attacks on them.

Ryabkov also warned NATO member countries to stop supporting Ukraine. He said the US, together with other Western countries, have set their course to strategically defeat Russia.

Ryabkov said the destructive actions of the US and its allies are not only sparking an acute crisis in the Euro-Atlantics, but also threatening to cause the most serious upheavals in the Asia-Pacific region.

While Ryabkov was speaking, delegates from countries, including the US, European nations and Japan, joined their Ukrainian counterpart and walked out of the room in protest.

A UK envoy said that they wanted to show their support for Ukrainians in their country's fight for freedom, adding that "their fight is our fight."