TOKYO: US Ambassador to Japan Caroline Kennedy has publicly defended a controversial proposal to relocate a US Marine Corps base on Okinawa in southern Japan as the best of many options considered. She told journalists on Tokyo on Thursday in a news conference that America is grateful to the people of Okinawa for their support and is working hard to reduce the impact of its military bases on the island. The plan to move the Futenma air station to a less populated part of Okinawa has run into stiff opposition from residents and Okinawan officials who want it moved off their island completely. Kennedy also expressed confidence that the US Congress would ratify the Trans-Pacific Partnership, a trade pact with 12 nations, including Japan and the United States.