The White House has flatly ruled out national Covid-19 vaccination passports for Americans, saying citizens' privacy and rights should be protected.
Schemes to introduce such passports have been touted around the world as a way to enable safe circulation of people while fighting the pandemic.
The US said it did not and would not support a "system that requires Americans to carry a credential".America has lost more than half a million lives to the virus.
Nearly 31 million cases have been registered, making the US the country worst affected by the pandemic, figures from Johns Hopkins University indicate.
Addressing reporters, White House press secretary Jen Psaki said: "The government is not now, nor will be, supporting a system that requires Americans to carry a credential.
''"There will be no federal vaccinations database and no federal mandate requiring everyone to obtain a single vaccination credential."':Post too long. Click here to view the full text.