President-elect Joe Biden is moving quickly to fill out his administration and could name top leaders for his Cabinet as early as next week.

Biden told reporters on Thursday that he’s already decided on who will lead the Treasury Department. That pick, along with his nominee for secretary of state, may be announced before Thanksgiving, according to people close to the transition who spoke to The Associated Press on condition of anonymity to discuss internal deliberations.

The Cabinet announcements could be released in tranches, with groups of nominees focused on a specific top area, like the economy, national security or public health, being announced at once.

Such a move is intended to deliver the message that Biden is intent on preparing for the presidency even as President Donald Trump refuses to concede and attempts to subvert the election results in key states. Trump’s roadblocks have undermined core democratic principles such as the peaceful transfer of power and are especially problematic because Biden will take office in January amid the worst public health crisis in more than a century.

“It’s a huge impact. And each day it gets worse, meaning a week ago, it wasn’t that big of a deal. This week, it’s starting to get to be a bigger deal. Next week, it’ll be bigger,” said David Marchick, director of the Center for Presidential Transition at the nonpartisan Partnership for Public Service. “Every new day that’s lost has a larger impact than the day before.”

Still, Biden’s transition work is progressing, with the president-elect holding frequent virtual meetings from his home in Wilmington, Delaware, and a music venue downtown. At this point, Biden is deeply involved in choosing his Cabinet, a process described by one person as similar to fitting puzzle pieces together.