Biden likening Xi to a dictator 'extremely absurd, irresponsible': China

China's foreign ministry has slammed comments by US President Joe Biden equating Chinese leader Xi Jinping with "dictators" as an "open political provocation".

"The relevant remarks by the US side are extremely ridiculous and irresponsible, they seriously violate basic facts, diplomatic protocol and China's political dignity," foreign ministry spokesperson Mao Ning said at a Wednesday briefing.

"China is strongly dissatisfied with and firmly opposed to this," she added.

Russia also criticised Biden's comments, with the Kremlin on Wednesday saying the comment reflected Washington's "unpredictable" foreign policy.

"This is a very contradictory manifestation of US foreign policy, which points to a significant element of unpredictability," Kremlin spokesperson Dmitry Peskov told reporters.

The multi-faceted rivalry between China and the United States turned into a full-blown diplomatic crisis with February's balloon incident.

Beijing on Wednesday reiterated its protest against Washington's decision to shoot it down.

"The United States should have dealt with it calmly, rationally and professionally, but its distortion of facts, abuse of force, and escalation of hype have fully exposed its hegemonic and bullying nature," Mao said.

'Great embarrassment for dictators..'

Speaking at a fundraiser in California on Tuesday, Biden said Xi had been angered over an incident in February when a Chinese balloon – which Washington says was used for spying – flew over the United States before being shot down by American military jets.

His comments come just days after US Secretary of State Antony Blinken concluded a visit to Beijing aimed at re-establishing lines of communication in order to avoid conflict between the two global powers.

"The reason why Xi Jinping got very upset in terms of when I shot that balloon down with two box cars full of spy equipment is he didn't know it was there," Biden said.

"I'm serious. That was the great embarrassment for dictators, when they didn't know what happened."

Provocative statements

Biden, who at 80 is running for re-election, on Tuesday told donors that "we're in a situation now where (Xi) wants to have a relationship again."

Blinken "did a good job" on his Beijing trip, but "it's going to take time," Biden added.

The US president also brought up another prickly point regarding China: a recent summit in which leaders of Australia, India, Japan and the United States - known as the Quad group - sought to boost peace and stability in the Asia-Pacific maritime region.

The four countries are "working hand in glove in the South China Sea and the Indian Ocean," Biden said.

"What he (Xi) was really upset about was that I insisted that we unite the... so-called Quad," Biden said.

Tuesday was not the first time Biden has made provocative, statements at fund-raising receptions, usually small-scale events at which cameras and recordings are forbidden but where journalists may listen to and transcribe the president's opening remarks.

At one such event last October, for example, Biden spoke of the threat of nuclear "Armageddon" from Russia.