U.S. Vice President Joe Biden talks about rooting out corruption as he addresses a civil society forum during the U.S.-Africa Leaders Summit in Washington August 4, 2014.

U.S. President Barack Obama gestures with Vice President Joe Biden after his election night victory speech in Chicago, November 6, 2012.

U.S. Vice President Joe Biden gestures to the audience to sit down while receiving applause after being given the Athenagoras Human Rights Award from The Order of St. Andrew, Archons of the Ecumenical Patriarchate, in Manhattan, New York October 17, 2015. At left is Ambassador of Greece to the United States Christos Panagopoulos.

U.S. Vice President Joe Biden (L) grabs the arm of House Speaker John Boehner (R-OH) as President Barack Obama delivers his State of the Union address in front of the U.S. Congress, on Capitol Hill in Washington, January 28, 2014.

U.S. Vice President Joseph Biden talks on a mobile phone after boarding an Amtrak train at Union Station in Washington, to travel to the 30th Street Station in Philadelphia February 8, 2011.

U.S. Vice President Joe Biden is seen in a plane window after landing in Vilnius March 18, 2014.

Joseph Biden (L), takes the Oath of Office with wife Jill holding the family bible as Vice President of the United States on the West Front of the U.S. Capitol in Washington, January 20, 2009. Barack Obama became the first black U.S. president on Tuesday and declared it is time to set aside petty differences and embark on a new era of responsibility to repair the country and its image abroad.

U.S. Vice President Joe Biden waves as he boards Air Force Two at Yokota Air Base on the outskirts of Tokyo August 24, 2011.

Democratic Vice Presidential nominee U.S. Senator Joe Biden (D-DE) hugs his son Beau Biden (R), after being introduced by his son at the 2008 Democratic National Convention in Denver, Colorado, August 27, 2008. Democrats nominated Senator Barack Obama (D-IL) on Wednesday as their presidential candidate in a historic first for a black American, sending him into battle against Republican John McCain.

U.S. Vice President Joe Biden announces he will not seek the 2016 Democratic presidential nomination during an appearance with his wife Jill (R) in Rose Garden of the White House in Washington October 21, 2015.

Democratic vice presidential nominee Senator Joe Biden (D-DE) (L) and Republican vice presidential nominee Alaska Governor Sarah Palin (R) smile as they chat onstage at the end of their vice presidential debate at Washington University in St. Louis, Missouri, October 2, 2008.

U.S. President Barack Obama (2nd L) and Vice President Joe Biden (L), along with members of the national security team, receive an update on the mission against Osama bin Laden in the Situation Room of the White House, May 1, 2011. Also pictured are Secretary of State Hillary Clinton (2nd R) and Defense Secretary Robert Gates (R). Please note: A classified document seen in this photograph has been obscured at source. Picture taken May 1, 2011.

US Democratic presidential candidate Senator Barack Obama (D-IL) waves with his vice presidential running mate Senator Joe Biden (D-DE) at the Old State Capitol in Springfield, Illinois, August 23, 2008.

U.S. Vice President Joe Biden (L) makes a point in front of Republican vice presidential nominee Paul Ryan and moderator Martha Raddatz (C) during the vice presidential debate in Danville, Kentucky, October 11, 2012.

U.S. Senator Ted Kennedy (D-Ma) (L) and Senator Joe Biden (D-De) confer during the first day of Judge John Roberts' Supreme Court confirmation hearings before the U.S. Senate Judiciary Committee on Capitol Hill in Washington, September 12, 2005. The U.S. Senate opened its first Supreme Court confirmation hearing in 11 years on Monday with Chief Justice nominee Roberts ready to explain his judicial beliefs and background to Republicans and Democrats.

Sen. Joe Biden (D-DE) speaks to reporters in front of a Danish U.N. armoured personnel carrier at the airport in Sarajevo, Bosnia April 9, 1993. REUTERS/Chris Helgren

Former U.S. Vice President Joe Biden poses for a selfie after addressing the International Association of Fire Fighters in Washington, U.S., March 12, 2019.

U.S. President Barack Obama and Vice President Joe Biden practice their putting on the White House putting green on the South Lawn in this handout photograph taken on April 24, 2009 and later released by the White House.

Democratic Vice Presidential Nominee U.S. Senator Joe Biden (D-DE) smiles while addressing the 2008 Democratic National Convention in Denver, Colorado, August 27, 2008. Democrats nominated Senator Barack Obama (D-IL) on Wednesday as their presidential candidate in a historic first for a black American, sending him into battle against Republican John McCain.

Vice President Joseph Biden places his hand on his heart as the casket of his son is carried into the church before a funeral mass for former Delaware Attorney General Beau Biden at St. Anthony of Padua Church in Wilmington, Delaware June 6, 2015.

Democratic presidential candidate Senator Joe Biden (D-DE) speaks with supporters during a campaign stop at the Public Library in Allison, Iowa November 27, 2007.

U.S. Vice President Joe Biden (C) stands behind reporters as President Barack Obama and U.N. Secretary-General Ban Ki-moon make statements after their meeting in the Oval Office at the White House in Washington, D.C., United States August 4, 2015.