Japan has sounded out the United States about relocating the Futenma air station by building a heliport at U.S. Marine Corps Camp Schwab in Nago, Okinawa, instead of constructing an airfield with two runways off the camp as per a 2006 accord, several government sources said Friday.

But Chief Cabinet Secretary Hirofumi Hirano denied making any proposals to Washington on the stalled relocation of U.S. Marine Corps Air Station Futenma, saying the government is still considering its options on a "zero base" level.

He said the government's task force on finding a relocation site for the base is still studying possible locations.