U.S. President Joe Biden will host a virtual COVID-19 vaccine summit on Wednesday to push wealthier nations to do more to get the pandemic under control.

Timed to coincide with the United Nations General Assembly, the meeting will prod more countries to follow the lead of the U.S., which has donated more doses than any other.

In remarks at the U.N. Tuesday, Biden took credit for sharing more than 160 million doses with other countries.

The World Health Organization has long decried vaccine inequity between rich and poor countries.

Only 15 percent of promised donations of vaccines have been delivered, according to the WHO.

The health agency has also repeatedly called for a global moratorium on booster shots to help ease the drastic inequity in vaccine distribution.