A key nuclear treaty between the US and Russia has ended and the UN chief has described the event as a "grave moment" for international peace and security.

MOSCOW, Feb 5 (Reuters) - Russia has repeatedly supplied oil to Cuba in recent years, and will continue to do so, Russia's ambassador to Cuba Viktor Coronelli said in an interview with state news agency RIA.

Many of America's closest partners are exploring opportunities with China following clashes with President Donald Trump over tariffs and his demands to take over Greenland from NATO ally Denmark

Since the collapse of the old Soviet Union, Russia has cut a substantially diminished figure on the international stage.

A Russian official said Moscow is ready to respond with military measures if the United States deploys its missile defense program to Greenland.

Russia has saud that India is free to purchase crude oil from any country, while rejecting claims that New Delhi has agreed to halt imports from Moscow.

The delegations from Moscow and Kyiv were joined in the United Arab Emirates by U.S. special envoy Steve Witkoff and Jared Kushner.

Russian President Vladimir Putin has discussed the burgeoning economic cooperation between Moscow and Beijing and their relations with the United States in a video call with Chinese leader Xi Jinping.

Russia launched its biggest missile and drone attack on Ukraine so far this year on Tuesday, according to Ukrainian authorities, cutting heat to tens of thousands of people and ending a brief reprieve agreed to by Moscow and Washington as Ukrainians grapple with plummeting winter temperatures.