President Donald Trump claimed to be personally overseeing the U.S. vaccine program during an Oval Office press briefing.

The president and his economic advisers spoke to reporters Thursday, and the president said he was in charge of "Operation Warp Speed," a White House initiative that reportedly promised to deliver 300 million doses of a vaccine that could be ready by January.

"I'm not overpromising, I don't know who said it, but whatever the maximum is, whatever you can humanly do, we're going to have," Trump said, "and we hope you're going to come up with a good vaccine. Johnson & Johnson, Oxford, lots of different great companies, representatives of our country in some ways. [National Institutes of Health] is working very hard and doing a terrific job. No, I hope you're going to have a vaccine, and we are going to fast-track it like you've never been seen before, if we come up with the vaccine. I think they probably will."

"You know is in charge of it, honestly, I am," he added. "I'll tell you, I'm really in charge of it. I could say somebody else, I will say we are dealing with, as you know, the general and the admiral. We are very much in charge. I think probably more than anything, I am in charge. I'm the one that gets blamed, I get blamed anyway. Don't forget, if we come up with a vaccine in record time, they'll say I should have done it faster. We have a lot of good possibilities."