WASHINGTON/WILMINGTON, Del:After weeks of defiance, President Donald Trump on Monday allowed officials to proceed with a transition to President-elect Joe Biden, giving his Democratic rival access to briefings and funding even as he vowed to persist with efforts to fight the election results.

Trump, a Republican, has alleged widespread voter fraud in the Nov. 3 election without providing evidence. Although he has not acknowledged Biden's victory, his announcement on Monday was the closest he has come to admitting defeat.

The General Services Administration, which is the federal agency that must sign off on presidential transitions, told Biden on Monday that he could formally begin the hand-over process. GSA Administrator Emily Murphy said in a letter that Biden would now have access to resources that had been denied to him because of the legal challenges seeking to overturn his win. 

That announcement came shortly after Michigan officials certified Biden as the victor in their state, making Trump's legal efforts to change the election outcome even more unlikely to succeed.

Trump and his advisers said he would continue to pursue legal avenues, but his tweet served as a sign that even the White House understood it was getting close to time to move on.

"Our case STRONGLY continues, 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," Trump said in a tweet.

A Trump adviser painted the move as similar to both candidates getting briefed during the campaign, and said the president's tweet was not a concession.

A statement by the Biden transition said meetings would begin with federal officials on Washington's response to the coronavirus pandemic, along with discussions of national security issues.

The move by the GSA means Biden's team will now have federal funds and an official office to conduct his transition until he takes office on Jan. 20. It also paves the way for Biden and Vice President-elect Kamala Harris to receive regular national security briefings that Trump also gets.

Two Trump administration officials told Reuters the Biden agency review teams could begin interacting with Trump agency officials as soon as Tuesday.

Earlier on Monday, Biden named the top members of his foreign policy team, tapping trusted aide Antony Blinken to head the State Department and former U.S. senator, secretary of state and 2004 Democratic presidential nominee John Kerry to serve as his special climate envoy.