Spokeswoman Jen Psaki says in a statement that officials from the U.S. Embassies in Kuala Lumpur, Malaysia, and Beijing are in contact with families of the passengers. The department says it's working to determine if other U.S. citizens may have been on the flight.
No additional information was released.
The Malaysian Airlines aircraft went missing early Saturday on a flight from Malaysia to Beijing. Vietnamese air force planes report spotting a pair of large oil slicks in the area where the Boeing 777 disappeared.
Psaki extended condolences to the loved ones of passengers on Malaysian Airlines Flight MH370.
Picture caption: This Friday, Aug. 10, 2012 photo shows the broken wing of a Malaysian Airline Boeing 777-200 passenger jet a day after it collided with the tail of a China Eastern Airline A340 plane, at Pudong International Airport in Shanghai, China. The same Boeing 777-200 has vanished Saturday, March 8, 2014 less than an hour after it took off from Kuala Lumpur for Beijing. AP