Joe Biden, the US president-elect, will pick veteran diplomat Antony Blinken as secretary of state, a person close to Mr Biden's team said on Sunday, adding that an announcement is likely on Tuesday.
Mr Blinken is a longtime confidant of Mr Biden who served as deputy secretary of state and as deputy national security adviser in Barack Obama's administration, in which Mr Biden served as vice president.
Mr Blinken's appointment made Jake Sullivan, another longtime aide of Mr Biden, the lead candidate for his national security adviser. Bloomberg earlier reported the expected nomination.
The president-elect's transition team declined to comment and Mr Blinken did not respond to a request for confirmation.
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Mr Blinken, 58, has long held the view that the US needs to take an active leadership role in the world or see that role filled by countries like China.
"As much of a burden as it sometimes seems to play ... the alternative in terms of our interests and the lives of Americans are much worse," he told Reuters in October.
People familiar with his management style describe Mr Blinken as a "diplomat's diplomat" – deliberative and relatively soft-spoken, but well-versed in the day to day processes of foreign policy.
After Democratic presidential nominee Hillary Clinton lost the 2016 election to President Donald Trump, Mr Blinken became one of the founders of WestExec Advisors, a Washington consultancy advising corporations on geopolitical risks.
Having practiced law briefly, he entered politics in the late 1980s, helping Democrat Michael Dukakis's presidential campaign raise money.
Mr Blinken joined Democratic president Bill Clinton's White House as a speechwriter and became one of his national security aides.
Under Mr Obama, Mr Blinken worked to limit most US combat deployments to small numbers of troops. But he told Reuters last year that Mr Trump had "gutted American credibility" with his withdrawal of US troops in Syria in 2019 that left Kurdish US allies relatively isolated in their fight against ISIS.
On the campaign trail, Mr Blinken was one of Mr Biden's closest advisers, even on issues that went beyond foreign policy.
That trust is the product of the years Mr Blinken worked alongside Mr Biden as an adviser to his unsuccessful 2008 presidential campaign, as national security adviser early in his vice presidency and as the Democratic staff director of the Senate Foreign Relations Committee when Mr Biden was its chair.