Moscow's top diplomat landed in the eastern city of Huangshan early Wednesday for a series of meetings about the future of Afghanistan.

But Russia's bloody assault on Ukraine is likely to loom large over proceedings.

Beijing has refused to condemn the invasion and has provided a level of diplomatic cover for an increasingly isolated Russia.

US officials have accused China of signalling "willingness" to provide military and economic aid to Russia, while President Joe Biden has compared the invasion of Ukraine to China's crushing of protests in Tiananmen Square in 1989.

But on Wednesday, Lavrov painted a picture of a new world order, saying the world was "living through a very serious stage in the history of international relations".

"We, together with you, and with our sympathisers will move towards a multipolar, just, democratic world order," Lavrov said in a video released by the Russian foreign ministry ahead of a meeting with Chinese Foreign Minister Wang Yi. 

The two ministers were shown on Chinese state TV in face masks bumping elbows in front of their national flags.

A readout from the Chinese foreign ministry quoted Wang Yi saying that "China-Russia relations have withstood the new test of the changing international situation, maintained the correct direction of progress and shown tenacious development momentum."

Foreign ministry spokesman Wang Wenbin told reporters earlier that Moscow and Beijing will continue efforts in "advancing global multipolarity and the democratisation of international relations".

Wang added that "China-Russia cooperation has no limits", repeating a line used by President Vladimir Putin and his Chinese counterpart Xi Jinping to characterise ties.

"Our striving for peace has no limits, our upholding of security has no limits, our opposition towards hegemony has no limits," Wang said.

Afghanistan

Lavrov will attend a series of meetings hosted by China to discuss ways to help Afghanistan, with diplomats from the United States and the Taliban-led country's neighbours also expected to attend. 

China shares only a sliver of a border with Afghanistan, but Beijing has long feared its neighbour could become a staging point for Muslim Uyghur separatists from Xinjiang.

The meetings follow a visit by Wang last week to Kabul, his first trip to Afghanistan since the Taliban seized power.

China and Russia have become closer in recent years, with Putin notably attending the opening ceremony of the Beijing Winter Olympics last month only days before the invasion of Ukraine.

The strongman leader and China's Xi signed energy deals worth billions of dollars during Putin's trip.