FILE - In this Jan. 9, 2020, file photo former Secretary of State John Kerry smiles while speaking at a campaign stop to support Democratic presidential candidate former Vice President Joe Biden at the Biden for President Fort Dodge Office in Fort Dodge, Iowa. (AP Photo/Andrew Harnik, File)

FILE - In this Feb. 1, 2020, file photo Democratic presidential candidate former Vice President Joe Biden smiles as former Secretary of State John Kerry, left, takes the podium to speak at a campaign stop at the South Slope Community Center in North Liberty, Iowa. (AP Photo/Andrew Harnik, File)

FILE - In this Thursday, Sept. 29, 2016, file photo, Deputy Secretary of State Antony Blinken testifies on Capitol Hill in Washington, before the Senate Foreign Relations Committee hearing on Syria. Blinken is the leading contender to become President-elect Joe Biden's nominee for secretary of state, according to multiple people familiar with the Biden team's planning. (AP Photo/Jose Luis Magana, File)

FILE - In this Thursday, Sept. 29, 2016, file photo, Deputy Secretary of State Antony Blinken testifies on Capitol Hill in Washington, before the Senate Foreign Relations Committee hearing on Syria. Blinken is the leading contender to become President-elect Joe Biden's nominee for secretary of state, according to multiple people familiar with the Biden team's planning. (AP Photo/Jose Luis Magana, File)

FILE - In this Jan. 9, 2014, file photo Assistant Secretary of State for African Affairs Linda Thomas-Greenfield, right, testifies during a Senate Foreign Relations Committee hearing on Capitol Hill in Washington. President-elect Joe Biden is expected to tap longtime diplomat Linda Thomas-Greenfield as the U.S. ambassador to the United Nations. (AP Photo/Pablo Martinez Monsivais, File)