WASHINGTON — President-elect Joseph R. Biden Jr. on Tuesday criticized the velocity of vaccine distribution beneath the Trump administration and promised to step up the tempo when he takes workplace, whereas delivering a sober warning in regards to the toll of the coronavirus pandemic.

Mr. Biden provided a bleak evaluation of the months forward, saying they’d be “a really robust interval for our nation,” and he exhorted Individuals to make the sacrifices vital to beat the devastation of the virus.

“It’s going to take all of the grit and willpower we’ve as Individuals to get it achieved,” he stated.

He warned that if the present tempo of administering vaccines beneath President Trump continued, “it’s going to take years, not months,” to vaccinate the nation. And he stated he had directed his group to organize a extra aggressive effort as soon as he takes workplace in three weeks, pledging “to maneuver heaven and earth to get us moving into the correct path.”

“That is going to be the best operational problem we’ve ever confronted as a nation,” Mr. Biden stated throughout an deal with in Wilmington, Del., “however we’re going to get it achieved.”

Mr. Biden will assume the presidency amid a well being disaster that has already killed more than 336,000 people in america and inflicted widespread financial disruption. Distributing vaccines to the American individuals will pose an early check for him.

Earlier this month, federal officers had stated their purpose was for 20 million individuals to get their first photographs of a vaccine by the tip of the 12 months. As of Monday morning, 11.4 million doses of the Pfizer and Moderna vaccines had been despatched out throughout the nation, however simply 2.1 million individuals in america had acquired their first dose, in accordance with a dashboard maintained by the Centers for Disease Control and Prevention, which most probably displays a reporting lag of a number of days.

Mr. Biden has vowed to get 100 million vaccine shots into the arms of Individuals in his first 100 days in workplace; vaccination at present requires two photographs, which might recommend that about 50 million individuals could be vaccinated in that point.

On Tuesday, Mr. Biden introduced new members of his Covid-19 response group, together with coordinators to deal with vaccinations, testing and provide chain administration.

Operation Warp Velocity, the Trump administration’s effort to fast-track the event and rollout of vaccines, spent billions of dollars to assist drug firms check and manufacture their vaccines and be certain that they’d have a purchaser. These investments helped vaccines turn into obtainable a lot sooner than many specialists had predicted.

Nonetheless, getting these vaccines into arms has gotten off to a slower begin than federal officers had hoped.

“We definitely are usually not on the numbers that we needed to be on the finish of December,” Dr. Anthony S. Fauci, the federal government’s prime infectious illness skilled, stated on CNN on Tuesday. However he added, “I imagine that as we get into January, we’re going to see a rise within the momentum.”

Moncef Slaoui, the scientific adviser to Operation Warp Velocity, stated as recently as last week that the chances have been excessive that the primary 100 million individuals in america could be immunized by the tip of March.

Michael Pratt, a spokesman for the Division of Well being and Human Companies, defended the tempo of the vaccine rollout. He stated in an announcement that it was “a testomony to the success of Operation Warp Velocity” that 20 million doses had already been made obtainable to states and different jurisdictions. (Not the entire doses have been shipped.) And Mr. Trump stated in a tweet that it was “as much as the States to distribute the vaccines as soon as dropped at the designated areas by the Federal Authorities.”

The tempo of inoculation in america is anticipated to choose up within the first months of subsequent 12 months as extra vaccine provide turns into obtainable and extra services start giving it out to a wider collection of Individuals. Thus far, vaccines have been given primarily to well being care employees at hospitals and to residents of nursing properties and different long-term care services.

In his remarks on Tuesday, Mr. Biden stated he may “see a return to normalcy within the subsequent 12 months,” however he additionally provided an ominous forecast for the close to future. “We have to metal our spines for what’s forward,” he stated, including that the following few months could possibly be “the hardest throughout this whole pandemic.”

“I do know it’s onerous to listen to, but it surely’s the reality,” he stated.

He expressed hope that Mr. Trump, who has resisted sporting a masks and mocked Mr. Biden through the marketing campaign for sporting one, may nonetheless affect the general public in a optimistic method.

“It could make an enormous distinction for President Trump to say, ‘Put on masks,’” Mr. Biden stated. “I hope the president will clearly and unambiguously urge all Individuals to take the vaccine as soon as it’s obtainable.”

Hours earlier than Mr. Biden spoke, Vice President-elect Kamala Harris acquired her first dose of a Covid-19 vaccine. The shot was administered on reside tv, simply as Mr. Biden’s was final week when he received the Pfizer vaccine at a hospital in Delaware.

Ms. Harris acquired the Moderna vaccine at United Medical Middle, a public hospital in Southeast Washington. She inspired Individuals to get vaccinated as properly, saying: “It’s comparatively painless. It occurs actually shortly. It’s secure.” Her husband, Doug Emhoff, additionally acquired the vaccine on Tuesday.

State and native officers have lengthy stated they need more money to distribute and administer vaccines. The $900 billion reduction package deal that Mr. Trump signed into regulation on Sunday units apart greater than $8 billion for vaccine distribution, roughly in step with the $8.4 billion that well being departments requested from Congress. The C.D.C. in September had sent $200 million to the states for the hassle, adopted by another $140 million this month.

The federal government has stated the purpose is to permit anybody who needs a vaccine to get one by June, but it surely has not but secured sufficient provide of vaccines which were approved to be used. The USA has secured commitments for sufficient vaccine to vaccinate 200 million of the roughly 260 million grownup Individuals who’re eligible to be inoculated.

Moderna has agreed to supply 200 million doses of its vaccine to america, with the primary half coming by the tip of March and the second half coming by the tip of June.

Pfizer has additionally agreed to supply 200 million doses. With every particular person requiring two photographs, it leaves the provision 120 million doses brief.

Over the summer season, earlier than its vaccine had been proven to be efficient, Pfizer agreed to supply an preliminary 100 million doses to america. On the time, the government passed on an offer from Pfizer to lock in extra provides.

However because it turned clear that extra doses have been wanted, the federal government resumed talks with Pfizer. In a deal announced last week, Pfizer agreed to supply an extra 70 million doses by the tip of June and one other 30 million by the tip of July.

As a part of the deal, the federal government agreed to invoke the Protection Manufacturing Act, a Korean Warfare-era regulation that enables the federal government to extra shortly safe key provides by forcing suppliers to prioritize orders from a selected contractor. Operation Warp Velocity has thus far used the Protection Manufacturing Act 18 instances, together with to assist produce glass vials and syringes, in accordance with the Division of Well being and Human Companies.

Mr. Biden stated on Tuesday that he would additionally make use of the Protection Manufacturing Act upon taking workplace, saying he would “order personal trade to speed up the making of the supplies wanted for the vaccines in addition to protecting gear.”

The federal government has just a few avenues for offering vaccines to the 60 million American adults not lined by the prevailing offers with Pfizer and Moderna.

It could possibly train choices to purchase extra doses from Pfizer or Moderna. The federal government may additionally flip to vaccines from different producers anticipated to report late-stage ends in the approaching weeks. Johnson & Johnson is anticipating outcomes late subsequent month from a trial of its single-shot vaccine, a format that may make it simpler to ship than the vaccines from Pfizer and Moderna. And a U.S. trial evaluating a two-shot vaccine developed by AstraZeneca and the College of Oxford may have ends in February.

On Tuesday, Mr. Biden acknowledged he was not but accountable for the federal government’s virus response, saying, “My potential to alter the path of this pandemic begins in three weeks.” And he made clear that he would wish assist from Congress subsequent 12 months to supply extra funding to hold out his plans.

However at the same time as he warned in regards to the troublesome weeks and months forward, he struck an optimistic word about the long term.

“We’re going to get by means of this,” he stated. “Brighter days are coming.”

Thomas Kaplan reported from Washington, and Rebecca Robbins from Bellingham, Wash.