President-elect Joe Biden has named Ron Klain as his White House chief of staff.

Mr Klain, who is married to attorney and environmental activist Monica Medina, has worked closely with Joe Biden since the 1980s, serving as a top aide in the Senate and during Biden’s stint as vice-president.

Paying tribute to Mr Klain following his appointment, Mr Biden said: "His deep, varied experience and capacity to work with people all across the political spectrum is precisely what I need in a White House chief of staff as we confront this moment of crisis and bring our country together again."

Ron Klain will start his new role following Joe Biden's inauguration on January 20 (Getty Images)

Responding to the appointment, Klain said: “It’s the honor of a lifetime to serve President-elect Biden in this role, and I am humbled by his confidence.”

Career of Ron Klain

Regarded as one of Washington’s great insiders, Klain has served as a close adviser to both Joe Biden and former vice-president Al Gore.

Mr Klain served as a law clerk for Supreme Court Justice Byron White in 1987 and 1988 after graduating from Harvard Law School.

From 1989 to 1992 he served as chief counsel on the Senate Judiciary Committee when the president-elect was serving as chairman. He also worked as a speechwriter for Mr Biden during his unsuccessful 1998 and 2008 presidential campaigns.

From 1995 to 1999 during the Clinton presidency he served as chief-of-staff to vice-president Al Gore, before serving as General Counsel of Gore's Recount Committee during Gore’s ill-fated 2000 presidential campaign.

Mr Klain would return to work with Mr Biden in 2009 serving as the then-vice-president’s chief of staff.

President Obama would put Mr Klain in charge of the country’s Ebola response in 2014, experience that could prove crucial during a global pandemic.

He reportedly fell out with Mr Biden in 2015 when he opted to back the Hillary Clinton presidential campaign.

Klain is an outspoken critic of the Trump administration. In October he claimed that Trump and his support team had “walked off the battlefield” by failing to properly implement a Covid-19 response.

What does the White House chief of staff do?

Once known as the Secretary to the President of the United States the White House chief of staff is regarded as the gatekeeper to the White House and the president.

They are charged with overseeing policy development, daily operations, and staff activities for the president.

The political appointment doesn’t require senate approval, but is regarded as one of the most powerful roles in American politics, partly due to the role’s daily contact with the president.

Outgoing president Donald Trump’s current chief of staff is Mark Meadows.

Ron Klain: who is president-elect Joe Biden’s new White House chief of staff - and what does his role involve?