White House chief of staff Mark Meadows on Friday pressed Food and Drug Administration chief Stephen Hahn to grant an emergency use authorization for Pfizer's coronavirus vaccine by the end of the day or face possible firing, two administration officials said.

The vaccine produced by Pfizer Inc. and its German partner BioNTech won a critical endorsement Thursday from an FDA panel of outside advisers, and signoff from the agency — which is expected within days — is the next step needed to get the shots to the public.

FILE - A woman holds a small bottle labeled with a US On Verge of Launching COVID VaccinationsFood and Drug Administration has approved vaccine by Pfizer and Germany’s BioNTech

The FDA is not required to follow the guidance of its advisory committees, but often does.

Meadows spoke to Hahn by telephone on Friday, according to a senior administration official who was familiar with the conversation but was not authorized to discuss private conversations.

Hahn disputed characterizations of his conversation with Meadows.

The chief of staff also told Hahn his job was in jeopardy if the emergency use authorization was not issued before Saturday, said a second administration official familiar with the conversation.