Multiple news agencies, citing unnamed sources, have reported that longtime Iowa Gov. Terry Branstad has accepted a post as U.S. ambassador to China.

Former Des Moines Register political reporter Jennifer Jacobs, now with Bloomberg, broke the story late Tuesday night.

Branstad, the longest-serving governor in U.S. history, met with President-elect Donald Trump in New York City on Tuesday, but declined to answer reporters' questions about the position. Trump had said during the campaign that Branstad, a close friend of Chinese President Xi Jinping, would be a valuable asset in negotiations with China.

Branstad spokesman Ben Hammes told The Des Moines Register that the reports are "premature" and "unconfirmed," but many expect an announcement when Trump's victory tour visits Des Moines on Thursday. The Register's Jason Noble reported the political domino effect that would follow a Branstad-to-China confirmation, including the ascension of Lt. Gov. Kim Reynolds to the governorship with two years left on the term. That development could derail the governorship aspirations of Agriculture Secretary Bill Northey and Cedar Rapids Mayor Ron Corbett, a former House speaker.

Branstad has made several trade visits to China since returning to the governor's office, and Xi visited Iowa in 2012, shortly before taking power in China. Branstad has known Xi since 1985, when Xi was a provincial official in the Community Party and visited Iowa to learn about farming techniques.