Chinese leader Xi Jinping on Tuesday hailed his country's ties with Russia in a "chaotic" world as he met President Vladimir Putin at the BRICS summit in Kazan.

"The world is undergoing profound changes unseen in a century, and the international situation is chaotic and intertwined," Xi told Putin, praising the "profound friendship" between their two countries.

China and Russia, Xi said, "have continuously deepened and expanded comprehensive strategic coordination and practical cooperation".

Ties have "injected strong impetus into the development, revitalization and modernization of the two countries," the Chinese leader said.

And they have "made important contributions to upholding international equity and justice," he added.

Moscow and Beijing have forged closer ties since Russia launched its military offensive in Ukraine in February 2022, an alliance that has caused anxiety in the West as both countries seek to expand their global influence.

China and Russia declared a "no limits" partnership shortly before Moscow launched its attack on Ukraine, which Beijing has never condemned.