Chinese President Xi Jinping is unlikely to abandon his "old friend" Vladimir Putin, even as the Russian leader's decision to send thousands more troops to Ukraine and his nuclear threats strain Beijing's "no limits" partnership with Moscow, experts said.

China will instead dig in on its awkward stance of calling for dialogue and peaceful resolution while refusing to condemn Russia's invasion of Ukraine, they said.

On Thursday, Foreign Minister Wang Yi told his Russian counterpart Sergey Lavrov on the sidelines of the United Nations General Assembly in New York that China would to stick to an "objective" and "fair" position.