A US military spokesman said he had no information but, if confirmed, it would be the first time the two allies have conducted a joint exercise on Baengnyeong island, near the disputed sea border in the Yellow Sea.
The reports came as US Secretary of State Hillary Clinton headed to South Korea for talks with President Lee Myung-Bak.
SBS TV and Chosun daily said special troops from the two allies will conduct the drill around the middle of next month.
An unidentified military source was quoted by Chosun as saying a hovercraft base at Goampo on the North's southwestern coast was expected to be completed in June.
