While the vast majority of cases have been in China, the virus has spread to some two dozen countries abroad, including five British nationals infected in a French mountain resort.
The American man died on Thursday in Wuhan, epicenter of the virus outbreak in the central Chinese province of Hubei, a U.S. embassy spokesman said in Beijing on Saturday. He did not elaborate.
A Japanese man in his sixties and hospitalized with pneumonia in Wuhan, capital of Hubei, also died after suffering symptoms consistent with the new coronavirus, Japan's foreign ministry said.
The virus has been a blow to China's already-slowing economy, with Goldman Sachs cutting its first-quarter GDP growth target to 4% from 5.6% previously and saying a deeper hit is possible.