President Joe Biden was expected to discuss that milestone and more later Tuesday in remarks updating the public on the U.S. strategy to slow the spread of coronavirus abroad.

The announcement comes amid a rise in infections in the U.S., fueled by the highly contagious delta strain of the virus, which led U.S. public health officials last week to recommend that people who have been fully vaccinated against COVID-19 resume wearing face coverings in some public indoor settings.

Biden promised the U.S. would be an “arsenal” of vaccines for the world. The United States has sent the most vaccines overseas of any donor country.

But while notable, the 110 million doses the U.S. has donated largely through a global vaccine program known as COVAX represent a fraction of what is needed worldwide.

In a statement Tuesday, the White House stated that 500 million doses Pfizer vaccine will be shipped by the United States at the end August. It has also pledged to deliver 100 low-income countries Pfizer vaccines by June 2022.

As a result of widespread vaccine hesitancy, the pace of domestic vaccinations in the United States slowed to 110 million doses.

Approximately 90 million eligible Americans over 12 have not received a single dose of vaccine.

Biden had promised to send more than 80,000,000 doses abroad by June 30, but was only able to share a small fraction of this due to regulatory and logistical hurdles in the recipient countries.

Through July, the pace of shipment increased significantly.

Biden’s sharing program allows for 75% of U.S. doses to be shared via COVAX. This plan aims to aid lower- and mid-income countries, while the rest is sent to U.S. allies and partners.

The White House insists nothing is being asked in return for the shots. This contrasts its approach to Russia, China and other countries that it claims have used their vaccines domestically as a tool to geopolitical leverage.