WASHINGTON – The General Services Administration said Monday that Joe Biden is the “apparent winner” of the Nov. 3 election, clearing the way for the start of the transition from President Donald Trump’s administration and allowing Biden to coordinate with federal agencies on plans for taking over Jan. 20.

Trump, who hasn’t conceded the election, said in a tweet that he is directing his team to cooperate on the transition but is vowing to keep up the fight.

GSA Administrator Emily Murphy made the determination after “recent developments involving legal challenges and certifications of election results.” Michigan certified Biden’s victory Monday, and a federal judge in Pennsylvania tossed a Trump campaign lawsuit on Saturday seeking to prevent certification in that state.

Yohannes Abraham, executive director of the Biden transition, said in a statement that the decision “is a needed step to begin tackling the challenges facing our nation.”

Murphy, a Trump appointee, had faced criticism for failing to begin the transition process sooner, preventing Biden’s team from working with career agency officials on plans for his administration.

“Please know that I came to my decision independently, based on the law and available facts. I was never directly or indirectly pressured by any Executive Branch official – including those who work at the White House or GSA – with regard to the substance or timing of my decision,” Murphy wrote in a letter to Biden.

Trump tweeted shortly after her letter was made public: “We will keep up the good fight and I believe we will prevail! Nevertheless, in the best interest of our Country, I am recommending that Emily and her team do what needs to be done with regard to initial protocols, and have told my team to do the same.”

Pressure had been mounting on Murphy as an increasing number of Republicans, national security experts and business leaders said it was time for that process to move forward.

Sen. Lamar Alexander, R-Tenn., who has repeatedly called for the transition to begin, released a new statement Monday saying that Trump should “put the country first” and help Biden’s administration succeed.

“When you are in public life, people remember the last thing you do,” Alexander said.

Republican Sen. Rob Portman of Ohio on Monday called for Murphy to release money and staffing needed for the transition. Portman, a senior member of the Senate Homeland Security and Governmental Affairs Committee, also said Biden should receive high-level briefings on national security and the coronavirus vaccine distribution plan.

Alexander and Portman joined a growing number of Republican officials who in recent days have urged Trump to begin the transition. Sen. Shelley Moore Capito, R-W.Va., also urged a smooth transition, saying Monday that “at some point, the 2020 election must end.”

Meanwhile, more than 160 business leaders asked Murphy to immediately acknowledge Biden as president-elect and begin the transition to a new administration. “Withholding resources and vital information from an incoming administration puts the public and economic health and security of America at risk,” the business leaders said in an open letter to Murphy.

Separately, more than 100 Republican former national security officials – including former Homeland Security Director Tom Ridge, former CIA Director Michael Hayden and former Director of National Intelligence John Negroponte – said in a statement that Trump’s refusal to concede and allow for an orderly transition “constitutes a serious threat” to America’s democratic process. The officials signing the letter worked under four Republican presidents, including Trump.

Trump has publicly refused to accept defeat and launched a series of losing court battles across the country making claims of widespread voter fraud and seeking to overturn the election results.