China's top diplomat said on Tuesday that Beijing would strengthen strategic cooperation with Moscow, Russian state media reported, as he met his counterpart for talks.

Russian Foreign Minister Sergei Lavrov arrived in China for a two-day official visit on Monday, with the two countries looking to further solidify diplomatic ties as Russia's war in Ukraine grinds on.

China and Russia have in recent years ramped up economic cooperation and diplomatic contacts, and their strategic partnership has only grown closer since the invasion of Ukraine.

But analysts say China holds the upper hand in the relationship with Russia, with its sway growing as Moscow's international isolation deepens.

And in meetings on Tuesday, Wang Yi promised: "China will support Russia's stable development under the leadership of Putin."

"Beijing and Moscow will continue to strengthen strategic cooperation on the world stage and provide each other with strong support," Wang said, according to the RIA Novosti news agency.

"The support of the people is the source of progress in Russia," he added, according to the Russian state-owned newspaper Izvestia.

"I think that under the strong leadership of President Putin, the Russian people will have a bright future," he said.

Lavrov, in turn, thanked China for its "support" after President Vladimir Putin's recent re-election, in which he was unchallenged by any meaningful opposition.

"Xi Jinping... was among the first ones to send congratulations to the president-elect Putin, and we are overall grateful to our Chinese friends for this support," Lavrov said, according to a video of the meeting shared by Izvestia on Telegram.

"The election results confirmed the deep trust of the Russian people in our leader and the ongoing domestic and foreign policies," he added, according to RIA Novosti.

"This applies not least to the course to strengthen strategic interaction and partnership with the PRC," the top diplomat said, referring to China by its official acronym.

Lavrov last visited Beijing in October for an international forum on Chinese President Xi Jinping's flagship Belt and Road infrastructure initiative.

Western nations regularly urge China to wield its influence over Russia to bring about peace in Ukraine.

US officials have also warned Beijing against indirect aid to the Russian war effort.

In Brussels last week, US Secretary of State Antony Blinken told reporters that "China continues to provide materials to support Russia's defence industrial base".

And Treasury Secretary Janet Yellen, who wrapped up a visit to China on Monday, said she had warned officials of the consequences of supporting Russia's military procurement.