WILMINGTON, Del. — President Donald Trump’s refusal to cooperate with his successor is forcing President-elect Joe Biden to seek unusual workarounds to prepare for the exploding public health threat and evolving national security challenges he will inherit in just nine weeks.

Blocked from the official intelligence briefing traditionally afforded to incoming presidents, Biden gathered virtually on Tuesday with a collection of intelligence, defense and diplomatic experts. None of the experts is currently affiliated with the U.S. government, raising questions about whether Biden is being provided the most up-to-date information about dangers facing the nation.

Vice President-elect Kamala Harris received a more formal briefing Tuesday as a member of the Senate Intelligence Committee, though still has relatively limited information about the specific threats Biden will inherit.

And as the worst pandemic in a century bears down on the U.S. with renewed ferocity, the current administration is blocking Biden from collaborating with its response team. Biden’s representatives instead plan to meet directly with pharmaceutical companies this week to determine how best to distribute at least two promising vaccines to hundreds of millions of Americans, the biggest logistical challenge to face a new president in generations.

President-elect Joe Biden attends a national security briefing at The Queen theater, Tuesday, Nov. 17, in Wilmington, Del. AP Photo/Andrew Harnik

The moves reflect how Biden is adjusting to a historically tense transition. With no sign that Trump is prepared to facilitate soon a peaceful transfer of power, Biden and his team are instead working through a series of backup options to do the best they can to prepare for the challenges he will face as soon as he takes office in January.

Declining to criticize Trump, Biden acknowledged Tuesday that he has “not been receiving briefings that would ordinarily come by now” as he opened his virtual meeting with the national security experts. The 12 participants, who appeared on video screens, included former Deputy CIA Director David Cohen, retired Gen. Stanley McChrystal and Avril Haines, a deputy national security adviser in the Obama administration, among others.

Biden said he was preparing to inherit “a divided country and a world in disarray.”

“That’s why I need you all,” he said.

Weeks after the election, Trump continues to block Biden’s access to the administration’s pandemic and national security briefings, falsely claiming that Biden is not the legitimate president-elect because of non-existent voter fraud. The Democrat defeated the Republican president on Nov. 7, and Trump’s flailing legal strategy to block certification of the election results is quickly fizzling out.

White House press secretary Kayleigh McEnany said Wednesday on Fox News Channel that the Trump administration “is doing everything statutorily required” for a transition. But she blamed the General Services Administration, an obscure government agency whose leader, Emily Murphy, has yet to certify Biden as the winner, for stalling the process of officially launching the transition.

Trump, who has publicly refused to accept defeat, selected Murphy to lead GSA.

A study released Tuesday by the Center for Presidential Transition at the nonpartisan Partnership for Public Service warned that an abbreviated transition could impair Biden’s ability to fill the more than 1,200 administration jobs requiring Senate confirmation, including key Cabinet and sub-Cabinet posts on the front lines of addressing the pandemic.

A growing group of Republicans have begun to state publicly what Trump will not: Biden will become the next president on Jan. 20. Even Israeli Prime Minister Benjamin Netanyahu, a staunch Trump ally, referred to Biden as the American “president-elect” for the first time Tuesday.

“He isn’t getting the briefings that the president-elect should be getting, but that’s not going to stop him from doing everything he can to prepare and execute during this transition period,” said Biden transition spokesman T.J. Ducklo.

Trump’s decision to block the transfer of power has forced Biden to navigate the life-and-death business of vaccine distribution with limited information.

Biden’s team plans to meet with private pharmaceutical companies on its own in the coming days to learn more about the status of their vaccine production. While neither of the two most promising vaccines has yet earned U.S. government approval, they would almost certainly be distributed under Biden’s watch if and when they are formally deemed safe.

Currently under the Trump administration, the Department of Health and Human Services and the Pentagon are working in conjunction with states on a vaccine distribution plan. But the Biden transition team and Democrats in Congress also have ideas. There could be conflicting expectations for state leaders and health care systems, which will be closest to the actual work of putting shots into the arms of Americans.

Biden warned on Monday that “more people may die” if Trump continues to block his access to vaccine distribution plans and pandemic data.

The heads of the American Hospital Association, the American Medical Association and the American Nurses Association issued a joint statement Tuesday urging the Trump administration to share “all critical information related to COVID-19” with Biden.

“There are obvious limits to Biden’s approach.

Some of Biden’s current team of advisers on national security and foreign policy have held security clearances in their past jobs, but are not privy to real-time intelligence now. Others have security clearances in their current jobs, perhaps as employees of defense contractors. But right now, no member of the transition team can share classified intelligence with the Biden transition team, especially without being in a secured location.

Former Deputy CIA Director Michael Morell, in a recent interview with the Center for Presidential Transition, said it was imperative that Biden be briefed on the agency’s highly classified covert actions undertaken by the Trump administration, “because on Inauguration Day, these covert actions will become the new president’s.”

Meanwhile, serious foreign conflicts loom.

Trump, for example, is expected to withdraw a significant number of troops from Afghanistan in the coming weeks. The NATO leader on Tuesday criticized the decision, warning such a move could give terrorist groups an opening to organize attacks against the West.

___

Associated Press writers Ricardo Alonso-Zaldivar and Lisa Mascaro in Washington and Brian Witte in Annapolis, Maryland, contributed to this report.