'DECISIVE'
Mongolia, which has yet to confirm a case, placed its president, Battulga Khaltmaa, in quarantine as a precaution after he returned from a trip to China, state media reported.
Scientists say much remains unknown about the virus, which can lead to pneumonia, and a vaccine could take up to 18 months to develop.
A Chinese official called the epidemic the most difficult health crisis in the country's modern history. Another said some recovered patients had been found to be infectious, suggesting the epidemic may be even harder to eradicate.
In addition to stockpiling medical supplies, governments ordered schools shut and cancelled big gatherings to try to halt the flu-like disease known as COVID-19.
U.S. President Donald Trump's administration was considering invoking special powers to expand production of protective gear.
In Europe, France's reported cases doubled, Germany warned of an impending epidemic and Greece, a gateway for refugees from the Middle East, announced tighter border controls.
Read Also: Gold rises on pandemic fears; palladium scales new peak
Switzerland joined countries banning big events while the death toll in Italy, Europe's worst-hit country, rose to 17 and the number testing positive increased by more than 200 to 655.
Germany has about 45 cases, France about 38 and Spain 23, according to a Reuters count.
Tedros told reporters that Iran, Italy and South Korea were at a "decisive point" in efforts to prevent a wider outbreak.
