In a dramatic move to slow the spread of the coronavirus in one of the most affected regions of the country, the Roman Catholic Archdiocese of Seattle suspended all public celebration of Mass, effective immediately, becoming the first Catholic archdiocese in the country to do so.

“This is out of an extreme measure of caution,” the archbishop of Seattle, Paul D. Etienne, said in a video message on Wednesday. “Despite our best efforts, this epidemic is going to continue to spread.”

Priests, he said, should continue to privately celebrate the Eucharist each day.

It was the most significant example of how the coronavirus is increasingly disrupting religious life across the United States, from a mosque in the Seattle area that canceled traditional Friday prayer services last week to Kentucky, where the governor on Wednesday urged all churches to cancel services.

Also on Wednesday, the Episcopal bishops in Virginia and Washington, D.C., announced that all churches in the dioceses would be closed for two weeks, including the Washington National Cathedral, which has held presidential funerals and is a focal point of Christian life in the capital.