Pfizer CEO Albert Bourla told media outlets today that the company is negotiating a way to speed up the delivery of an additional 100 million doses of its COVID-19 vaccine to the U.S. next year.

Americans are expected to receive some of the first shots of the vaccine today — days after FDA granted an EUA for the Pfizer (NYSE:PFE) and BioNTech (NSDQ:BNTX) vaccine.

Pfizer so far has agreed to provide an initial 100 million doses of the vaccine to the U.S., with each person who receives it requiring two doses. It would likely take until the third quarter of 2021 for Pfizer to provide another 100 million doses for Americans, but Bourla told CNBC that the U.S. government is pushing to get the vaccines by the second quarter.

“We are working very collaboratively to try to find a solution and be able to allocate those 100 million [doses] in the second quarter if possible or a lot of them,” Bourla said. Pfizer doesn’t have an agreement with the U.S. yet.

Bourla told CNN that Pfizer and BioNTech expect to produce 1.3 billion doses of the vaccine over the next year, but 1.2 billion doses are already committed to other countries.

Former FDA commissioner Dr. Scott Gottlieb, a Pfizer board member, used a CNBC appearance to fault the U.S. government for turning down previous Pfizer offers for additional vaccine doses.

President Donald Trump has said he would invoke the Defence Production Act to secure more vaccines for Americans; Bourla thinks such a move would be “very positive” because it would help the company solve supply limitations.

Vaccines from other companies could also soon be on the way. Moderna’s COVID-19 vaccine candidate could receive an authorization as soon as this week, and vaccines from Oxford-AstraZeneca and Johnson & Johnson could win authorizations early next year.