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.
Eight Israeli airstrikes have hit the Abu al-Duhur military airbase in northwestern Syria early on Tuesday, targeting the runway and storage facilities, Syria's state-run Ekhbariya said, citing a military source.
Two students were killed in a shooting at a high school in the southern Philippines on Tuesday, one of them the gunman, officials said, in the second such incident in the country in less than two months.
The Supreme Court of Pakistan has ordered on Tuesday that former Prime Minister Imran Khan be moved to hospital from jail, his Pakistan Tehreek-e-Insaf party said, meeting a longstanding demand of his party and family, who had raised concerns about his health.
A Russian missile attack has killed 10 people and injured a further eight in a village in Ukraine's northeastern Kharkiv region, the regional governor said on Tuesday.
President Donald Trump said on Monday Iran would not make the deal he thinks is needed to end a war with the US and should surrender as talks between the countries remained stalled.