WASHINGTON (AP) The State Department said Wednesday that it has fired a U.S. diplomat over a romantic relationship he admitted having with a Chinese woman alleged to have ties to the Chinese Communist Party.

The dismissal is believed to be the first of its kind for violating a ban on such relationships that was introduced late last year under the Biden administration.

The Associated Press reported earlier this year that in the waning days of Democrat Joe Biden’s presidency, the State Department imposed a ban on all American government personnel in China, as well as family members and contractors with security clearances, from any romantic or sexual relationships with Chinese citizens.

Tommy Pigott, a State Department spokesman, said in a statement that the diplomat in question was dismissed from the foreign service after President Donald Trump and Secretary of State Marco Rubio reviewed the case and determined that he had “admitted concealing a romantic relationship with a Chinese national with known ties to the Chinese Communist Party.”

“Under Secretary Rubio’s leadership, we will maintain a zero-tolerance policy for any employee who is caught undermining our country’s national security,” Pigott said.

The statement did not identify the diplomat, but he and his girlfriend had been featured in a surreptitiously filmed video posted online by conservative firebrand James O’Keefe.

In Beijing, a Chinese government spokesperson declined to comment on what he said is a domestic U.S. issue. “But I would like to stress that we oppose drawing lines based on ideological difference and maliciously smearing China,” the Foreign Ministry’s Guo Jiakun said at a daily briefing.

Associated Press writer Ken Moritsugu in Beijing contributed to this report.