President Barack Obama has been briefed on the deadly Middle East Respiratory Syndrome, also known as MERS, after two cases were reported in the U.S., a White House spokesman said on Tuesday.
"Our team is watching it very closely," said spokesman Jay Carney.
Obama was briefed by Lisa Monaco, assistant to the president for homeland security and counterterrorism, Carney said.
Two cases of the deadly virus have been confirmed this month in Indiana and Florida. Both patients are health care providers who had been working in Saudi Arabia, where the virus was first reported in 2012.
The Centers for Disease Control and Prevention are taking the situation "very seriously" and working closely with local investigators, Carney said.
Officials are trying to reach out to hundreds of people who may have come into contact with the patients in the U.S. or while they were traveling from overseas.
The MERS virus has sickened at least 538 people in 14 countries. There is no vaccine or specific treatment, and little understanding of how the disease spreads.
So far, 145 people have died from MERS, which causes severe acute respiratory illness. Symptoms include fever, cough and trouble breathing.