President-elect Joe Biden plans to nominate seasoned diplomat Antony Blinken as his secretary of state, a decision likely to signal a return to multilateralism after Donald Trump's shunning of traditional allies, US media reported Sunday.

A mild-mannered policy wonk who is fluent in French and plays guitar on the side, the 58-year-old Blinken is a longtime aide to Biden who served as deputy secretary of state during Barack Obama's presidency.

Bloomberg, The New York Times and several other news organizations reported on the plan to nominate Blinken, quoting anonymous sources close to the president-elect.

The Washington Post and other news outlets said that the national security advisor job would go to Jake Sullivan, another veteran Biden aide known for his mastery of policy detail and lack of personal drama.

Ron Klain, the incoming White House chief of staff, told ABC News that Biden would make his first cabinet announcements on Tuesday.

Blinken, who would need Senate confirmation, could help reassure the United States' allies that have been shunned and at times insulted by Trump.

A committed Europhile, the New York-born Blinken went to high school in Paris -- where his stepfather, a Holocaust survivor, practiced law -- and later worked himself as an attorney in France.

Polished and courteous, he could hardly be more different in personality than the hard-charging outgoing secretary of state, Mike Pompeo.

But one common trait would be their close alliances with their bosses, with Blinken advising Biden since the president-elect's time as a senator.

Richard Haass, president of the Council on Foreign Relations, wrote on Twitter that Blinken would be a strong secretary of state.

Besides thorough knowledge of foreign policy, Blinken has "a relationship with his boss that allows him to speak truth to power and the authority to speak for his boss," Haass wrote.

'Standing up for our values'

Pompeo, a steadfast loyalist of Trump even as the president refuses to concede defeat, has put a priority on a more confrontational approach to China and containing Iran.

In remarks during the campaign, Blinken said he also saw China as a competitor but was willing to find areas on which to work with Beijing, including in fighting climate change and global pandemics such as Covid-19.

He faulted Trump's approach, saying that the president needlessly alienated US allies and had reduced American credibility by challenging democratic norms at home.

"We need to be standing up for our values and put them back at the center of our foreign policy, not walk away from them," Blinken told the Hudson Institute.

Blinken was closely involved in the Obama administration's sealing of a landmark 2015 nuclear accord with Iran that Trump exited.

Blinken has strongly criticized Trump's withdrawal, noting that Iran has since boosted its nuclear program and stepped up its support for regional proxies, even as its economy takes a hit from US sanctions.

Along with other Biden aides, Blinken has said that the United States should be willing to return to the Iran deal but at the same time seek a stronger and longer-lasting agreement.

The rival Republican Party will remain in charge of the Senate unless Democrats win both runoff elections in January in Georgia.

Republicans have made clear that they will exert their power over cabinet choices, but Blinken, well-known after his years working on the Senate Foreign Relations Committee, may be a comparatively non-controversial choice.