Chinese Ambassador to the US Xie Feng "made serious representations and strong protests to senior officials of the White House and the US Department of State on June 21" following President Joe Biden's comments likening Chinese President Xi Jinping to a dictator, the embassy said in a statement urging the United States to "take earnest action" or "bear all the consequences."
The statement, released Thursday, strongly rebukes the comments made by Biden, calling it a "smear" that "seriously contradicts basic facts, breaches diplomatic etiquette, infringes on China's political dignity, runs counter to the commitments made by the US side, and undermines mutual trust."
Speaking at a fundraiser in California, Biden compared the Chinese leader to a dictator, and claimed Xi was "embarrassed" because he was unaware of the spy balloon that transited the US earlier this year.
"The reason why Xi Jinping got very upset in terms of when I shot that balloon down with two boxcars full of spy equipment in it is he didn't know it was there. No, I'm serious. That's what's a great embarrassment for dictators, when they didn't know what happened," Biden said.
The US President's comments came mere days after US Secretary of State Antony Blinken was in Beijing for meetings with key officials, including Xi.
At the conclusion of that trip, Blinken said the US and China had made "progress" toward steering relations back on track as both sides agreed on the need to "stabilize" the bilateral relationship between the two superpowers.
"It was clear coming in that the relationship was at a point of instability," Blinken said at a news conference in the Chinese capital Monday. "And both sides recognized the need to work to stabilize it."
"We're not going to have success on every issue between us on any given day, but in a whole variety of areas, on the terms that we set for this trip, we have made progress and we are moving forward," he added.
Now, it appears that Biden's comments could undermine the "progress" that was made by the top US diplomat.
"The nature and impact are very negative," the Chinese Embassy statement said. "The Chinese government and people feel deeply affronted and firmly oppose it."
"We urge the US side to immediately take earnest actions to undo the negative impact and honor its own commitments. Otherwise, it will have to bear all the consequences," it says.
"President Biden said explicitly before that the United States respects China's system, does not seek to change it and has no intention for a new Cold War," it said. "But with the latest irresponsible remarks about China's political system and top leader, people cannot help but question the sincerity of the US side."
"The Chinese government and people do not accept any political provocation against China's top leader, and will resolutely respond," the statement said.
On Wednesday, the US State Department sought to downplay the potential impact of Biden's comments, with State Department deputy spokesperson Vedant Patel saying the remarks had "absolutely not at all" diminished the progress.
"It should come as no surprise, of course, that we have differences and disagreements with the PRC. And the President believes that diplomacy, including this recent trip undertaken by the Secretary, is a responsible way to manage tensions, clear up misperceptions, avoid miscalculations. And all of this is in our interests to do that," Patel said at a State Department briefing.
"That does not mean, of course, we will not be blunt and forthright about our differences," he continued. "And we look forward to continuing to engage on a number of issues as it relates to the complex relationship that we have with the PRC."
The statement from the Chinese Embassy does not specify to whom the ambassador made the "serious representations." CNN has reached out to the embassy, the State Department and the White House for comment.