WASHINGTON -- The top-ranking diplomat at the U.S. Embassy in Beijing has abruptly resigned, telling colleagues he is leaving the foreign service over disagreements with Trump administration policy, U.S. officials said Monday.

A CBS News source in the embassy confirms David Rank resigned over the U.S. withdrawal from the Paris climate accord.

The source says Rank called a town hall meeting of embassy employees Monday afternoon. Most people thought he was going to announce a visit by President Trump, but instead he announced his resignation, citing the decision to leave the Paris agreement as the reason.

The State Department confirmed Rank's retirement, saying it was a "personal decision" but offering no details about his reasons for stepping down.

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Rank was a 27-year career foreign service officer with experience in Afghanistan, Taiwan, Greece and Mauritius.

He was No. 2 at the embassy, in charge pending the arrival of Trump's new ambassador to China, former Iowa Gov. Terry Branstad, who was confirmed by the Senate last month.

Rank's resignation was first reported by John Pomfret, editor-at-large for the website, SupChina.

Mr. Trump announced America's withdrawal from a global climate change pact last week. That kept an election campaign promise, but fanned fears of the U.S. abdicating its global leadership role and shunning international consensus on the world's most pressing issues. Secretary of State Rex Tillerson was among Trump advisers who had been quietly lobbying for the U.S. to stay in the pact.

Cooperation with China on combating climate change was often cited by the Obama administration as an area in which Washington and Beijing were able to work together, despite tensions in other areas of the relationship.

China and the U.S. are the world's two largest emitters of manmade carbon dioxide, considered a top cause of climate change, and agreement between them on capping emissions helped pave the way for the Paris agreement among more than 190 nations.