Health and Human Services Secretary Alex Azar on Sunday admitted that the Trump administration's so-called "Warp Speed" vaccine effort could produce hundreds of millions of doses that are neither safe nor effective.

Azar made the remarks during an appearance on Face the Nation with host Margaret Brennan.

"Is the pledge 300 million Americans will be able to get a shot in their arm by the end of the year?" Brennan asked.

"That's a goal," Azar explained. "What happened is these drug companies and vaccine makers said it's all going to take this amount of time because they're using their traditional approaches."

"The president said that's not acceptable," he continued. "We're going to scale up commercial manufacturing and produce hundreds of millions of doses at risk. They may not pan out, they may not prove to be safe and effective but we'll have it so we can begin administration right away."