The U.S. ambassador to China is stepping down, Secretary of State Mike Pompeo announced Monday on Twitter.

Pompeo thanked Ambassador Terry Branstad on Twitter for his more than three years of service. There was no immediate confirmation from the State Department.

"Ambassador Branstad has contributed to rebalancing U.S.-China relations so that it is results-oriented, reciprocal, and fair," Pompeo wrote in a follow-up tweet.

In a statement, the U.S. embassy in Beijing confirmed the departure, saying Branstad was retiring and would leave Beijing next month. It added that he had confirmed his decision to President Donald Trump by phone last week.

Branstad was embroiled in a recent controversy when China's official People's Daily newspaper rejected an opinion column that he had written. It wasn't clear whether his departure was related to the piece.

Pompeo tweeted last week that China's ruling Communist Party refused to run Branstad's op-ed while the Chinese ambassador to the U.S. "is free to publish in any U.S. media outlet."

Chinese foreign ministry spokesperson, Zhao Lijian, responded that Branstad's article was "full of loopholes, seriously inconsistent with facts and wantonly attacks and smears China."

The U.S. Embassy had contacted the People's Daily on Aug. 26 about the piece, asking that it be printed in full without any edits before Sept. 4, the People's Daily said in a statement posted online.

Branstad, who arrived in Beijing in June 2017, is a native of Iowa and was governor of the major farming state for 22 years over two spans, from 1983 to 1999 and 2011 to 2017.

Early in his first term, he met Xi Jinping, now China's leader, when Xi visited Iowa as a county-level Communist Party official on a 1985 trade trip.

He was appointed ambassador by President Donald Trump after a vacancy of several months, during which the embassy's No. 2 official, David Rank, resigned after criticizing Trump's withdrawal from the Paris climate accord.

Soon after his arrival in Beijing, Branstad welcomed back American beef to the Chinese market after a 14-year ban, saying "I know it is a key priority of the president to reduce the trade deficit, and this is one of the ways we can do it."

He joined U.S. Trade Representative Robert Lighthizer and U.S. Treasury Secretary Steven Mnuchin at trade talks with Chinese counterparts in Beijing in May 2019.

He also made a rare visit to Tibet later that month, where he expressed concerns about what the U.S. called Chinese government interference in the freedom of Tibetan Buddhists to organize and practice their religion.

"He encouraged the Chinese government to engage in substantive dialogue with the Dalai Lama or his representatives, without preconditions, to seek a settlement that resolves differences," a U.S. Embassy statement said.