WASHINGTON - The Biden administration has withdrawn former president Donald Trump's nominee to be the United States ambassador to Singapore, leaving the vacancy available to be filled by a career diplomat or political appointee of President Joe Biden's choosing.

The withdrawal of businesswoman Barbera Hale Thornhill, announced alongside dozens of other names in a White House statement on Thursday (Feb 4), is standard practice for political appointees after a new president takes office.

Mr Trump had nominated Ms Thornhill, the president of a Los Angeles interior design firm, for the role in September 2019. The White House had then highlighted her business experience and her philanthropic work focusing on children affected by poverty, abuse and neglect.

Ms Thornhill was renominated on Jan 6 this year after the confirmation process, which involves vetting and a Senate hearing, stalled.

The role of US ambassador to Singapore has been vacant since January 2017, when the previous ambassador Kirk Wagar left his post following Mr Trump's inauguration. Mr Wagar, a political appointee, was the finance chair for then-President Barack Obama's election campaigns in Florida in 2008 and 2012.

Mr Rafik Mansour has been the US embassy's interim charge d'affaires in Singapore since July 2019, when he replaced Ms Stephanie Syptak-Ramnath.

Before Ms Thornhill's nomination, Mr Trump nominated former deputy national security adviser K.T. McFarland to the post in May 2017. She withdrew her nomination in February 2018 after senators questioned her role in the investigation over Russia's interference in the US election.