President Xi Jinping warned against "expanding" military ties on Wednesday in a speech at the opening ceremony of a virtual summit with leaders from Russia, India, Brazil and South Africa.

Xi told the Brics business forum that the "Ukraine crisis is... a wake-up call" and warned against "expanding military alliances and seeking one's own security at the expense of other countries' security".

He also called for solidarity and cooperation to support a global economic recovery threatened by an epidemic and security challenges.

The influential club of Brics emerging economies accounts for more than 40 percent of the global population and nearly a quarter of the world's gross domestic product.

Three of its members – China, India and South Africa – have abstained from voting on a UN resolution condemning Russia's attack on Ukraine.

In a call last week, Xi assured his Russian counterpart Vladimir Putin that China would support Moscow's core interests in "sovereignty and security".

Xi also took a swipe at US and European Union sanctions on Russia in the speech on Wednesday, saying "sanctions are a boomerang and a double-edged sword". (AFP/Reuters)