Chinese leader Xi Jinping on Tuesday unexpectedly skipped a business forum of the BRICS economic group in South Africa, sending his commerce minister instead to deliver a fiery speech in his name that decried US hegemony.

Xi, who arrived in Johannesburg on Monday for the annual BRICS summit of major emerging economies, was scheduled to deliver a speech at its business forum on Tuesday alongside leaders from India, Brazil and South Africa.

But the Chinese leader failed to show up at the event, with no official announcement or explanation from Beijing.

Instead, his prepared statement – peppered with thinly-veiled swipes at the United States that have become a fixture of Xi’s international speeches – was delivered by Chinese Commerce Minister Wang Wentao.

In the statement, Xi called for the world to avoid sleepwalking “into the abyss of a new cold war.”

Without directly mentioning the US, the statement said “some country, obsessed with maintaining its hegemony, has gone out of its way to cripple the emerging markets, and developing countries.”