(CNN)President-elect Joe Biden has tapped Ron Klain to be his incoming chief of staff, the Biden transition office said in a news release Wednesday, elevating his longtime aide to one of the most powerful positions in the White House.

Klain is one of Biden's most trusted campaign advisers and was long seen as the most likely pick for the top job. He previously served as chief of staff to Vice President Al Gore during the Clinton administration and Biden during his tenure as President Barack Obama's vice president.

"Ron has been invaluable to me over the many years that we have worked together, including as we rescued the American economy from one of the worst downturns in our history in 2009 and later overcame a daunting public health emergency in 2014," Biden said in a statement.