Defense Minister Toshimi Kitazawa met with his U.S. counterpart, Robert Gates, Thursday in Tokyo, with the two agreeing to speed talks on the possibility of providing jointly developed sea-based missile-shield systems to other countries and the need to prevent North Korea from taking further provocative actions.

Japan and the U.S. jointly developed the ballistic missile interception system, the Standard Missile-3, but a bilateral pact prohibits exporting it to third countries without prior consent from Japan. The U.S. is keen to boost its missile defense in Europe and wants SM-3 interceptors there.

"It makes economic sense to make it available to others and we will be working toward that end with the Japanese government," Gates told a joint news conference.

"I think it is fair to say that the minister acknowledged the economic benefit of being able to make it available, but we understand that there are certain processes that have to be gone through here in Japan before that is possible."

At the same news conference, Kitazawa said Japan "would aim to have an answer by the end of the year."

He also said he told Gates Japan was hoping to accelerate talks on transferring F-15 fighter drills from Okinawa to Guam as an option to alleviate the burden on the prefecture, about 19 percent of which is occupied by U.S. bases.

Gates and Kitazawa also reaffirmed the bilateral agreement on the contentious relocation of U.S. Marine Corps Air Station Futenma from Ginowan in Okinawa to Henoko in the northern part of the island.

"We do understand that it is politically a complex matter in Japan and we intend to follow the lead in the Japanese government in working with people of Okinawa to take their interests and their concerns into account," Gates said.