Nov. 11 (UPI) -- President-elect Joe Biden named longtime aide Ron Klain as his incoming White House chief of staff on Wednesday as he prepares to transition into the country's highest office despite its current occupant, President Donald Trump, having yet to concede defeat in the general election.
The Biden administration transition team announced Klain would oversee the president-elect's executive office and serve as his senior advisor in a statement Wednesday evening, stating the 59-year-old lawyer will work to build a diverse and experienced team to help Biden and Vice President-elect Kamala Harris "meet the urgent challenges facing the country."
Klain, a Harvard Law School graduate, has worked with Biden for decades, having advised the former senator from Delaware during his failed 1988 and 2008 presidential bids, worked as his chief counsel of the Senate Judiciary Committee in 1989 to 1992 and served as chief of staff to the vice president from 2009 to 2012. He also served as the White House Ebola Response coordinator under President Barack Obama during an outbreak of the deadly virus in 2014 and 2015.
Biden described Klain in a statement as "invaluable" during the years the pair have worked together.
"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," the president-elect said.
The announcement came more than a week after Election Day and days after Biden was named president-elect after being awarded 279 electoral votes, nine more than required, over the weekend.
While Biden and Harris work to transition into the White House, Trump -- who has filed numerous lawsuits for state recounts and to allege voter fraud and tabulation irregularities despite there being widespread consensus the election was held fairly -- continues to maintain that he will win the election.
Votes are still being counted in three states, with Arizona and Georgia leaning toward Biden and North Carolina toward Trump, all by slim margins, according to CNN and NBC. If Trump, who has 217 electoral votes, were to win all three, he'd still fall short of the 270 required to win the presidency.
"We will win!" Trump tweeted at least twice on Wednesday.
Elizabeth Warren, former presidential candidate and a Democratic senator from Massachusetts, called Klain "a superb choice for Chief of Staff."
"He understands the magnitude of the health and economic crisis and he has the experience to lead this next administration through it," she said via Twitter. "Ron has earned trust all across the entire Democratic Party."
Klain said in a statement that to serve Biden as his White House chief of staff is "the honor of a lifetime."
"I look forward to helping him and the Vice President-elect assemble a talented and diverse team in the White House as we tackle their ambitious agenda for change, and seek to heal the divides in our country," he said.