A spokesperson for China's permanent mission to the United Nations expressed indignation after a senior US diplomat held a virtual talk with Taiwan's leader, calling the move a breach of the US' political commitments on the island. 

"As permanent representative to the United Nations, Kelly Craft should reread the UN Charter and General Assembly resolution 2758 (1971). The United States should understand that the attempt to challenge the one-China principle receives no support and is doomed to fail," the spokesperson said. 

The delegation tweeted the statement on Wednesday night following a video conference between the US ambassador Kelly Craft and Taiwan's Tsai Ing-wen. 

The envoy, who is due to leave her post after the Biden administration takes over on Wednesday, tweeted that it was "a great privilege" to speak with Tsai.

"It is clearly stated in the Joint Communique on the Establishment of Diplomatic Relations between China and the United States released on 16 December 1978 that the United States recognizes the Government of the People's Republic of China as the sole legal Government of China, and within this context, the people of the United States will maintain cultural, commercial, and other unofficial relations with the people of Taiwan," the Chinese mission said.

"This move is a breach of the commitment the US has made to China and again proves the lack of integrity in the US government," it added. 

Zhang Jun, China's permanent representative to the UN, also tweeted opposition to the move by the American diplomat.  

"History proves time and again that no country can make itself great by making troubles for others. The troubles they make will only be troubles for the troublemakers themselves," the Chinese ambassador stated. 

Craft was scheduled to arrive in Taiwan on Wednesday for a three-day trip, but her journey, together with all senior-level overseas travels by the US State Department, was abruptly canceled by department officials this week, citing transition to the incoming Biden administration following the Jan 6 storming of the US Capitol by President Donald Trump's supporters.

"We are expecting shortly a plan from the incoming administration identifying the career officials who will remain in positions of responsibility on an acting basis until the Senate confirmation process is complete for incoming officials. As a result, we are cancelling all planned travel this week, including the Secretary's trip to Europe," read a statement released Tuesday by the State Department.

The visit by Craft was just announced last week by US Secretary of State Mike Pompeo. She would've been the third high-level US official to visit Taiwan since August, following trips made by US Secretary of Health and Human Services Alex Azar on Aug 9 and Under-Secretary of State for Economic Growth, Energy and Environment Keith Krach on Sept. 19.  

The outgoing secretary of state also announced on Saturday that the US is lifting "self-imposed restrictions" on contacts between American and Taiwan officials.

Michael D. Swaine, director of the Quincy Institute's East Asia Program, warned that the "these eleventh-hour actions by the Trump administration" are intended to limit the options of the incoming Biden administration in dealing with Taiwan and the Chinese mainland.

"Such actions are dangerous and reckless because they threaten to destroy the foundation of normalized relations with the People's Republic of China, thereby greatly increasing the chances of conflict with Beijing," he wrote in an analysis.