As Republicans push back on aid for vaccines, congressional Democrats point fingers over the next steps.

Lawmakers and the White House thought they had a deal in March to offset the spending, in part by clawing money back from the states. But governors in both parties balked, as did some House Democrats, and the deal collapsed. At the White House, Mr. Biden warned that the administration was running out of money to pay for medications, vaccines and reimbursement of new care.

Then Mr. Romney brokered a compromise. He cut a deal with the White House and with Democrats for a slimmed-down $10 billion aid package. But Republicans blocked the package amid a fight over whether to attach a language extending a Trump-era policy that allows the government to block entry to immigrants seeking asylum during the pandemic.

With limited options, the White House announced that it would divert $10 billion from other programs to pay for Covid necessities, including vaccines and treatments.

The announcement infuriated Mr. Romney, who earlier this month accused the White House of giving Republicans “patently false” information by saying it was low on funding. Other Republicans, including Senator Richard Burr of North Carolina, the ranking member of the Senate health committee, are also displeased, and Mr. McConnell has shown no inclination to revive Covid relief talks.

Even so, Dr. Ashish K. Jha, Mr. Biden’s coronavirus response coordinator, told reporters last week that he was “an eternal optimist” and still hopeful that Congress would pass a Covid relief package.

And the White House press secretary, Karine Jean-Pierre, told reporters last week that in the view of the White House, the negotiations are still very much alive.

“Our fight for Covid funding is active and regular and robust,” she said, “because
Covid, as we all know, is not over and we risk even more severe and lethal consequences for American people if we do not secure this funding — even if members of Congress may think otherwise.”