The Chinese city where the outbreak began is seeking to test all its 11 million residents. The World Health Organization has stopped testing a treatment praised by President Trump, citing safety concerns.
President Vladimir V. Putin has announced that Russia will hold its Victory Day military parade, postponed because of the coronavirus, on June 24.
The Wuhan government is close to completing its citywide testing drive. Thousands of medical and other workers were mobilized in a feat that some health experts and residents had initially questioned.
But medical workers armed with coronavirus test swabs have scoured construction sites and markets to look for itinerant workers while others made house calls to reach older residents and people with disabilities. Officials aired announcements over loudspeakers urging people to sign up for their own good.