Blinken could be named as early as Tuesday, according to sources close to Biden, while Axios first reported Thomas-Greenfield's impending nomination.
A small but growing group of Republican lawmakers are calling on President Trump to begin the transition of power to President-elect Joe Biden, even as the incumbent refuses to concede and forges ahead with a series of legal challenges trying to overturn the results of the November 3 election. This is far above the 270 votes he needs. "You have to let those votes stand. People know the process". "I'd rather have a president who has more than one day to prepare".
Thomas-Greenfield, a Black woman who served as the assistant secretary of state for Africa under Obama, was meant to restore morale and help fulfill Biden's pledge to choose a diverse cabinet, Axios reported.
The 58-year-old is a long-time aide to the president-elect.
The winning candidate will then be officially sworn in as president on Inauguration Day - January 20.
Long-time diplomat Ms Thomas-Greenfield is expected to be appointed as U.S. ambassador to the UN. Former president George W. Bush has also congratulated Biden.
Last Thrusday, Joe Biden speaking in response to the question on economic sanctions on Beijing and his remark on the country during the presidential debate, said that he wants to make sure that China plays by the rules.
What about the calls for Trump to concede?He has made repeated allegations of widespread electoral fraud, without providing any evidence.
Former New Jersey Governor Chris Christie, a prominent Trump ally, called the president's legal team a "national embarrassment".
"I've been a supporter of the president's". I voted for him twice. "Elections have consequences, and we can not continue to act as if something happened here that didn't happen".
"We're beginning to look like we are a banana republic", Maryland's Republican Gov. Larry Hogan, a frequent Trump critic, said on CNN's "State of the Union". He suggested that Trump's undermining of the presidential election could damage Republicans' prospects in runoff elections next month for Georgia's two Senate seats, contests that will decide which party controls the Senate.
The retiring senator went on to call Biden president-elect and noted that he was disappointed in the outcome, but said it was time to move on so Trump could preserve what he sees as a legacy of achievements in office.
Republican Senator Kevin Cramer told NBC's "Meet the Press" program that the start of the presidential transition process is overdue, though he declined to recognize Mr. Biden's victory.
But Trump's refusal to concede has raised concerns that he could cause long-term damage to public trust in the voting system that underlies United States democracy.
What's the latest with the challenges?
A Pennsylvania judge on Saturday threw out Donald Trump's claims of widespread electoral fraud there, dealing a new blow to the Republican's bid to overturn his loss in the U.S. presidential election.
Trump's General Services Administration (GSA) has yet to acknowledge that Biden won the election - a determination that would remove those roadblocks.
The Trump campaign had originally sought a recount of the entire state, costing around $US7.9 million ($10.8 million).
Trump again tweeted on Sunday about "massive and unprecedented fraud", an assertion dismissed by a long list of judges in several states. But Trump and Republican leaders have been putting pressure on the state's canvassing board to delay certification.
They asked for a delay of two weeks to allow for a full audit of results in Wayne County, the state's largest and where majority-black Detroit is located, which was won overwhelmingly by Biden. The most potentially effective law, the Hong Kong Human Rights and Democracy Act, which Trump only reluctantly signed, was co-sponsored by Republican Marco Rubio and Kamala Harris, the Democrats' Vice-President-elect.