The United States will share with other countries an additional 20 million doses of coronavirus vaccines, raising its total supply for international distribution to 80 million doses by the end of June, the White House said Monday.

The administration of President Joe Biden announced in late April that it will share its stock of 60 million doses of AstraZeneca Plc's coronavirus vaccine, which is yet to be authorized in the United States. But Biden said his country has now decided to share vaccines that have been authorized for use domestically as well.

U.S. President Joe Biden addresses a joint session of Congress in the House chamber of the U.S. Capitol on April 28, 2021 in Washington (Getty/Kyodo)

"Our nation is going to be the arsenal of vaccines for the rest of the world," Biden said, while emphasizing that the United States will be sharing vaccines more than any other country to date, including China and Russia known for seeking to expand their influence through "vaccine diplomacy."

"We will not use our vaccines to secure favors from other countries," he said.

The United States will work with the U.N.-backed COVAX facility, an international vaccine distribution platform, and other partners to ensure that the COVID vaccines are delivered in a way that is equitable and follows the science and public health data.

Working with the world's democratic nations, the United States will coordinate a multilateral effort to end the coronavirus pandemic, Biden said, adding that he hopes to announce progress in the area at the Group of Seven summit to be held in Britain in June.

The United States will continue to donate its excess supply of vaccines, but that "won't be nearly enough" to beat the pandemic, he said, calling for an "entirely new effort" involving working with pharmaceutical companies and partner nations to vastly increase supply.

U.S. regulators have authorized three coronavirus vaccines for emergency use in the country -- one developed by U.S. pharmaceutical giant Pfizer Inc. and its German partner BioNTech SE, another by U.S. company Moderna Inc. and a third by Johnson & Johnson.