Obama says US-Japan treaty applies to disputed Senkaku Islands ahead of visit

President Barack Obama confirmed Wednesday that America's mutual security treaty with Japan applies to the islands at the center of a territorial dispute between China and Japan.

"The policy of the United States is clear," he said in a written response to questions published in Japan's Yomiuri newspaper before his arrival in Tokyo at the start of a four-country Asia tour.

"The Senkaku islands are administered by Japan" and therefore fall under the U.S.-Japan treaty, he wrote. "And we oppose any unilateral attempts to undermine Japan's administration of these islands."

His statement seems aimed at reassuring Japan that the U.S. would come to its defense if China were to seize the islands, known as the Diayou in China. Russia's annexation of Crimea has sparked concern about America's political will to protect Asian allies, notably in Japan and the Philippines.

Obama said the United States is deepening its ties with China, but "our engagement with China does not and will not come at the expense of Japan or any other ally."

He told the Yomiuri that the U.S. will continue to take steps to reduce the impact of its military presence in Okinawa, but added "it's important to remember that the U.S. Marine Corps presence on Okinawa is absolutely critical to our mutual security. It plays a key role in the defense of Japan."