WASHINGTON — Moncef Slaoui, the chief scientist leading the White House’s Operation Warp Speed, said President Donald Trump’s public pressuring of the Food and Drug Administration commissioner last week to quickly approve the coronavirus vaccine was not helpful for building public confidence in the inoculation campaign.

Trump on Twitter and his chief of staff Mark Meadows privately lambasted FDA commissioner Stephen Hahn last week for moving too slowly before the FDA issued an emergency authorization on Friday for an authorization for the vaccine produced by Pfizer Inc.

Asked about the pressuring of Hahn, Slaoui said on Fox News Sunday that “if that phone call happened, I think it was useless and unfortunate, so are some of the tweets.”

An Associated Press-NORC Center for Public Affairs Research published last week found only about half of Americans are ready to take the vaccine.

Slaoui also urged Americans to keep an open mind about the vaccine and warned that the virus will continue to plague the nation beyond the spring if too few people take it.