U.S. President Joe Biden has finalized a deal to buy an additional 200 million coronavirus vaccine doses from Pfizer, Inc. and Moderna, Inc.

The doses should be delivered by the end of July.

The purchase is part of the Biden administration's efforts to deliver on the president's promise of inoculating the entire population by midsummer.

"We've now purchased enough vaccine supplies to vaccinate all Americans. Now we're working to get those vaccines into the arms of millions of people," Biden said during an address at the National Institutes of Health Thursday.

Biden said that both Moderna and Pfizer had committed to expediting their delivery by a month. This means that the companies will be delivering the 100 million doses they had promised by May instead of June.

"That's a month faster. That means lives will be saved," Biden said.

Biden said that the accelerated deliveries and the additional order should mean that there will be enough doses to inoculate 300 million Americans. He added that the administration and health care officials are working "around the clock" to ensure that there are enough vaccines to go around and personnel to administer them.

Biden said that health care agencies have already deployed more than 1,000 federal staff at major vaccination sites around the country over the last three weeks.

Biden admitted that the administration had faced a lot of setbacks to its plan to roll out the vaccines in time. He said that this was mainly due to the misleading information they were handed by the previous administration in terms of the true supply of vaccines that were obtained.  

"My predecessor, to be very blunt about it, did not do his job. We won't have everything fixed for a while. But we're going to fix it," Biden said.

Biden said that he was very "upset" when he discovered that they were not given all of the facts. He said that they were led to believe that there were significantly more vaccines than what was actually available.