• Biden announced Tuesday that states should open Covid-19 vaccine appointments to all U.S. adults by April 19
• A few weeks ago, Biden called on states, tribes and territories to make all U.S. adults eligible for vaccination no later than May 1.
• Biden announced the new deadline after his visit to a vaccination site in Alexandria, Virginia.

President Joe Biden announced Tuesday that states should open Covid-19 vaccine appointments to all U.S. adults by April 19, moving up his original deadline by nearly two weeks.

Biden announced the new deadline after he visited a vaccination site in Alexandria, Va. The deadline, though voluntary, applies public pressure to states that haven't already expanded their eligibility guidelines.

From the White House, Biden urged Americans to continue to practice pandemic safety measures, saying the U.S. isn't "at the finish line yet" and may still experience more "disease and misery" before the Fourth of July.

"The virus is spreading because we have too many people who see the end in sight think we're at the finish line already," Biden said. "We're still in a life and death race against this virus."

White House Press Secretary Jen Psaki earlier Tuesday confirmed Biden would announce the new deadline for states. She added that it doesn't mean every American will get the vaccine "that day."

"It means they can join the line that day, if they have not already done that beforehand," Psaki said during a White House news briefing.

A few weeks ago, Biden called on states, tribes and territories to make all U.S. adults eligible for vaccination no later than May 1. However, most states have already announced plans to open eligibility to all adults by April 19. Only Hawaii and Oregon haven't already announced plans to have open eligibility by that date, according to NBC News.

Biden announced last week that 90% of adults in the U.S. would be eligible for Covid-19 shots by April 19 and will be able to get them within 5 miles of their home under an expanded vaccination plan. Roughly 40,000 pharmacies will distribute the vaccine, up from 17,000, the president said, and the U.S. is setting up a dozen more mass vaccination sites by April 19.

"For the vast, vast majority of adults, you won't have to wait until May 1. You'll be eligible for your shot on April 19," Biden said March 29 during a news conference on the government's Covid-19 response and vaccination efforts around the country.

Biden also announced Tuesday that the U.S. has reached 150 million shots administered within his first 75 days in office.

The president is pushing to have 200 million Covid shots administered within his first 100 days in office. As of last week, the pace of U.S. vaccinations has been averaging about 3.1 million doses per day, Andy Slavitt, the White House's senior pandemic advisor, said Monday.

More than 40% of adults have had at least one shot, Slavitt said. He added that 75% of seniors have now received at least one shot, and more than half are fully vaccinated.

Even as the pace of vaccinations picks up, highly contagious variants are rapidly spreading, potentially stalling the nation's recovery from the pandemic.

Last week, CDC Director Dr. Rochelle Walensky said B.1.1.7, the variant first identified in the U.K.,  is starting to become the predominant strain in many regions of the U.S., accounting for 26% of Covid-19 cases circulating across the nation.

Walensky said Wednesday she expects to see more infections in the U.S. due to the transmissibility of the B.1.1.7 variant. She urged the public to continue pandemic safety measures, such as washing hands, wearing masks and practicing social distancing.

"This is a critical moment in our fight against the pandemic," Walensky said Wednesday. "We can't afford to let our guard down."