"The UK did not do it as carefully," he told Fox News. "If you go quickly and you do it superficially, people are not going to want to get vaccinated."
"The way the FDA is, our FDA is doing it, is the correct way," he said on Fox News. "We really scrutinise the data very carefully to guarantee to the American public that this is a safe and efficacious vaccine."
The FDA plans to meet on 10 December to discuss approval for the UK-approved vaccine, which was created through a partnership between Pfizer and BioNTech.
They will meet again on 17 December to discuss a second vaccine - Moderna's - request.