Watch Live: Biden to announce donation of 500 million COVID-19 vaccine doses abroad

Washington — President Biden on Thursday will deliver remarks on the COVID-19 vaccination program as his administration prepares to buy 500 million doses of Pfizer's coronavirus vaccine for the global supply. 

Mr. Biden's speech will cap the end of his first full day in the United Kingdom, where he touched down Wednesday for the Group of 7 summit. The trip is his first outside the United States since assuming office in January.