WILMINGTON, Del. (AP) — In a meeting with governors, Joe Biden expressed concern Thursday that President Donald Trump's unprecedented attempt to block the peaceful transition of power at the White House has hindered the flow of information about programs to fast-track a coronavirus vaccine.

“Unfortunately, my administration hasn’t been able to get everything we need,” the president-elect said during a video conference with the National Governors Association’s leadership team, which includes five Republicans and four Democrats.

He specifically cited “Operation Warp Speed,” the federal government's partnership with private pharmaceutical companies to develop a COVID-19 vaccine.

Biden participated from a theater in Wilmington, Delaware, with Vice President-elect Kamala Harris. Also appearing online were the leaders of Biden's virus task force: Vivek Murthy, a former surgeon general; David Kessler, an ex-head of the Food and Drug Administration; and Marcella Nunez-Smith of Yale University.

Among the Democratic governors participating was Gretchen Whitmer of Michigan, which has been among those Trump has targeted for unfounded claims of fraud.

“I want you to know that I will be your partner in the White House,” Biden told the governors, including Republicans Larry Hogan of Maryland, Asa Hutchinson of Arkansas, Kay Ivey of Alabama, Charlie Baker of Massachusetts and Gary Herbert of Utah.

Biden promised state leaders that he would “make sure you get the resources you need ... to beat this virus.”

Hogan told The Associated Press recently that Trump’s wild and unsupported claims of widespread voter fraud were “dangerous” and “embarrassing.”

Hutchison said over the weekend that Biden would be the next president and he called on the Trump administration to give Biden access to the intelligence briefings he needs in order to be fully prepared to lead the country on Jan. 20, Inauguration Day.

So far, the governors have not swayed the Republican president.

Before Biden's meeting, Trump came out with a new round of false claims of voter fraud in key states, even as courts continue to reject his challenges, and a small, but growing number of Republican officeholders publicly begin to accept Biden's victory.

Beyond being a pillar of democracy, the orderly transfer of power after an election is especially critical this year given the extraordinary governing challenges Biden will inherit in just nine weeks. The United States is struggling through the worst public health crisis in a century, state and local government are facing massive budget shortfalls, and millions of Americans remain out of work.

But more than two weeks after the Nov. 3 election, the Trump administration is refusing to let Biden receive detailed briefings on national security and pandemic planning that leaders in both parties say are vital to ensure Biden can govern effectively on Day One.

With Trump dug in and Republicans on Capitol Hill largely unwilling to challenge him, Biden has been forced to turn to diverse collection of outside allies to ratchet up the pressure on Trump to concede.

The CEOs of America's largest companies have released a statement recognizing Biden and Harris as the clear winners. The heads of the American Hospital Association, the American Medical Association and the American Nurses Association issued a joint statement on Tuesday urging the Trump administration to share “all critical information related to COVID-19” with Biden. Not doing so, they warned, would jeopardize American lives.

Trump is showing no signs of giving in.

He is getting nowhere in the courts, and his scattershot effort to overturn Biden’s victory is shifting toward obscure election boards that certify the vote. The battle is centered in the states that sealed Biden’s win. In Michigan, two Republican election officials in the state’s largest county initially refused to certify results despite no evidence of fraud.

The officials then backtracked and voted to certify before flipping again on Wednesday and saying they “remain opposed to certification.” Some Republicans have called on the GOP statewide canvassers to so the same as Trump applies pressure from his social media accounts.