Tokyo ? U.S. Secretary of State Hillary Rodham Clinton says a possible missile launch hinted at by North Korea should not be carried out.

Clinton, in Japan on her first trip abroad as President Barack Obama’s chief diplomat, said today that such a launch would hurt relations.

She told a news conference: “The possible missile launch that North Korea is talking about would be very unhelpful.”

On Monday, the 67th birthday of North Korean leader Kim Jong Il, Pyongyang claimed it has the right to “space development” — a term it has used previously to disguise a missile test as a satellite launch. When North Korea test-fired a long-range missile in 1998, it claimed to have put a satellite into orbit. Intelligence indicates the North may be planning another launch.

Clinton kicked off the official program of her first overseas trip in Tokyo today, visiting a Japanese cultural site and meeting U.S. Embassy staff.

Clinton participated in a purification rite and welcoming ceremony at a Shinto shrine to the father of modern Japan, Emperor Meiji.

Later today, Clinton will sign an agreement to move about 8,000 Marines on the Japanese island of Okinawa to the U.S. Pacific territory of Guam. About 20,000 of the 50,000 American troops in Japan are based in Okinawa, and their presence is often a source of tension in U.S.-Japan relations.

Japan, led by a deeply unpopular government and struggling with dire economic woes, is particularly jittery at the moment, and Clinton is aiming to reassure the country of its importance in the international arena.