UPDATED: March 10, 11:30 p.m.

All Harvard courses will move to remote instruction beginning March 23 as a result of a growing global coronavirus outbreak, University President Lawrence S. Bacow announced in an email Tuesday morning. The University will also ask students not to return from spring break.

"Students are asked not to return to campus after Spring Recess and to meet academic requirements remotely until further notice," Bacow wrote. "Students who need to remain on campus will also receive instruction remotely and must prepare for severely limited on-campus activities and interactions. All graduate students will transition to remote work wherever possible."

The move follows both similar decisions at other Ivy League universities in recent days and rapid changes on campus. As the number of confirmed coronavirus cases in Massachusetts rises, events and venues have closed, travel restrictions have tightened, and University affiliates have questioned how the disease will affect life and work on campus. Harvard has seen similarly seismic changes to operations only in wartime.

Spring recess officially begins this Saturday and concludes on March 22. The next day, students will attend classes virtually — a possibility Harvard University Health Services director Giang T. Nguyen and Dean of the Faculty of Arts and Sciences Claudine Gay first raised at a faculty meeting earlier this month. Since then, tabs for the online meeting platform Zoom have popped up on course websites and many faculty have tested it with their classes.

Bacow wrote Monday that Harvard will now strongly discourage gatherings of more than 25 people, a change from the previous guidance to rethink events of 100 or more.

"Despite our best efforts to bring the University’s resources to bear on this virus, we are still faced with uncertainty—and the considerable unease brought on by uncertainty," Bacow wrote. "It will take time for researchers, a good many of them who are our colleagues, to understand enough about this disease to mount a reliable defense against it. Now more than ever, we must do our utmost to protect those among us who are most vulnerable, whether physically or emotionally, and to treat one another with generosity and respect."

The University previously took a number of steps to reduce risk to affiliates, including launching a dedicated coronavirus website and cancelling Visitas, the visiting weekend for the Class of 2024.

It remains unclear how the outbreak will affect other spring events like alumni reunions, Class Day, and Commencement exercises.