The US Food and Drug Administration on Monday gave full approval to the COVID-19 vaccine made by Pfizer and German partner BioNTech for use in people over the age of 16.
It's the first such approval of a COVID-19 shot.
The vaccine has been authorised for emergency use since December and more than 204 million people in the United States have received it, based on Sunday's data.
But none of the three authorised COVID-19 vaccines had previously received full FDA approval.
Public health officials hope it will convince more unvaccinated Americans that Pfizer's shot is safe and effective.
Vaccine hesitancy among some Americans has hindered the United States response to the novel coronavirus.
"While millions of people have already safely received COVID-19 vaccines, we recognize that for some, the FDA approval of a vaccine may now instill additional confidence to get vaccinated," said Janet Woodcock, the US Food and Drug Administration's acting commissioner.
Roughly 51 per cent of Americans have been fully vaccinated so far, even as a recent surge of infections spurred by the contagious Delta variant ravages parts of the country with low vaccination rates.
An explosive-laden car rammed into a Pakistani military convoy on Saturday in a town near the Afghan border, killing at least 13 soldiers, sources said.
Radiation levels in the Gulf region remain normal after the 12-day Israel-Iran conflict severely damaged several nuclear facilities in Iran, Director General Rafael Mariano Grossi of the International Atomic Energy Agency (IAEA) said.
Rwanda and Democratic Republic of Congo signed a US-brokered peace agreement on Friday, raising hopes for an end to fighting that has killed thousands and displaced hundreds of thousands more this year.
The US Supreme Court on the last day of rulings for its current term gave Donald Trump his latest in a series of victories at the nation's top judicial body, one that may make it easier for him to implement contentious elements of his sweeping agenda as he tests the limits of presidential power.
Polish President Andrzej Duda arrived in Kyiv on Saturday for a meeting with Ukrainian President Volodymyr Zelenskyy, Duda's office said, as Kyiv aims to build support among allies at a critical juncture in its grinding war with Russia.