President Biden faces a new challenge in his COVID-19 messaging as much of the country remains unvaccinated despite significant progress in the early months of his administration.

The recent slowdown in the pace of daily vaccinations signals the U.S. is reaching a point where demand for the vaccine is waning, creating a major obstacle for Biden’s goal of returning to normalcy by the Fourth of July.

The declining vaccination rates come on the heels of accomplishments like making all Americans age 16 and older eligible for the vaccine earlier than expected, and as the U.S. closes in on getting doses to 200 million people before May 1.

"We’re at a tipping point where supply is no longer the issue, demand is the issue," said Lawrence Gostin, professor of global health at Georgetown University, who said he’s not overly concerned as most vaccine hesitant people are “implacably opposed.”

One former Trump administration official described the current stage of the pandemic as "the good, the bad and the ugly."

The good being declining case counts and millions of Americans who are getting fully vaccinated; the bad being the looming vaccine hesitancy; and the ugly being the growing crisis in India, which set a one-day global record for new cases when it reported 350,000 infections on Sunday.

Over the past few months, the Biden administration has been careful to set achievable goals to mark progress in fighting the pandemic, while also emphasizing that the COVID-19 battle is not yet over.

Last week, the good news of opening up vaccinations to all Americans was competing with the uncertainty raised by the decline in the seven-day average of daily vaccinations and the closure of mass vaccination sites in several states due to a lack of demand.

The U.S. hit a peak for its seven-day daily average of vaccinations on April 13 with 3.38 million doses in one day. Since then, vaccinations dropped to 3.19 million on April 18 and 2.75 million doses on Sunday, according to Our World in Data.

Multiple officials have downplayed any connection with the Johnson & Johnson vaccine and a more-than-weeklong pause in its distribution stemming from rare cases of blood clots. They said the one-dose shot is useful in hard to reach areas or in populations where it might be hard to get to come back for a second dose, but noted the administration has enough doses between the Pfizer-BioNTech and Moderna vaccines for the whole population and the issue is now convincing everyone to get their jab.

Progress has been made in vaccinations with more than 139 million U.S. adults receiving at least one dose of the COVID-19 vaccine as of Monday morning, amounting to almost 54 percent of the population. More than 95 million, or 37 percent of American adults, are fully vaccinated, according to the Centers for Disease Control and Prevention.

Democratic strategist Zac Petkanas noted that the Biden administration “far surpassed” its goals for vaccination rollout.

“They would be idiots to not take at least a partial victory lap and make sure that the American people how much was achieved against enormous odds,” he said.

“At the same time, it’s important that this isn’t suggesting that the mission is accomplished because there still are enormous obstacles to get over.”

For Americans who are frustrated by the remaining COVID-19 restrictions, Petkanas said the “strongest message that the White House can send” is: “If you’re tired of this shit, get vaccinated.”

In a sign that the U.S. is getting closer to pre-pandemic life, the Biden administration is expected on Tuesday to announce new masking guidance focused particularly on whether individuals need face coverings when outdoors. The White House was mum on details about whether it would only apply to those who are vaccinated and how lax the recommendations would be.

The easing of mask recommendations when outdoors reflects how the U.S. has progressed in the pandemic, and it underscores how studies have repeatedly shown the risk of transmission of COVID-19 is significantly lower when individuals are outdoors, especially if they are socially distanced.

But some officials wonder whether the administration has been too slow to move on offering less restrictive recommendations. Several states have already lifted mask mandates, and many Americans who have been reluctant to get the vaccine have pointed to the lack of incentives, reasoning it's not worth it if they'll still be asked to wear a mask once they get the shot.

“What we’ve seen is there’s a frustration among Americans in the hesitant category of ‘what is the point of getting a vaccine if it doesn’t change what I’m able to do?’” said Chris Meekins, a Health and Human Services official during the Trump administration.

Polls have shown vaccine hesitancy is prevalent among conservatives and Republicans, with a Washington Post-ABC News poll finding 55 percent of GOP respondents aged 18 to 39 and 40 percent of all Republicans saying they don’t plan to get vaccinated.

One former Trump administration official said overcoming vaccine hesitancy will be the biggest test thus far for Biden.

"I think that’s a problem we have and we don’t have a good plan for how to do it that I see so far. And they really need to figure something out and pick up the pace," the official said.

The Biden administration has made several efforts to increase support for vaccinations, including through its network of community leaders, advertising campaign and recent announcement of a tax credit for businesses that give employees paid leave for vaccinations and any necessary recovery.

But Leana Wen, an emergency physician and public health professor at George Washington University, said Biden has “a very narrow window” that may or may not have already closed to “tie reopening and getting back to normal with vaccination.”

“Rather, make the timeline about the individual,” said Wen, a former Baltimore city health commissioner. “You get back to normal at the point that you get vaccinated and are fully, or at least at the point that you are fully vaccinated. And I think that is what Biden really needs to focus on now.”