TOKYO -- U.S. Defense Secretary James Mattis reaffirmed the U.S.'s commitment to its defense treaty with Japan in a meeting with Japanese Prime Minister Shinzo Abe here on Friday. A Japanese official who attended the meeting said Mattis confirmed that the treaty extended to the Senkaku Islands -- which China claims and calls the Diaoyu -- in Okinawa Prefecture.
"I want there to be no misunderstanding during the transition in Washington that we stand firmly, 100%, shoulder to shoulder with you and the Japanese people," Mattis said at the start of the meeting.
Citing provocative actions by North Korea and "other challenges," the defense secretary said, "I want to make certain that Article 5 of our mutual defense treaty is understood to be as real to us today as it was a year ago, five years ago -- and as it will be a year, and 10 years, from now."
Under Article 5, the U.S. is required to defend territories under Japanese administrative control. Mattis also said the U.S. was committed to providing "extended deterrence" to its allies. Extended deterrence includes protecting allies under the U.S.'s nuclear umbrella.
Abe said he was convinced that, with the help of new U.S. President Donald Trump and Mattis, the U.S. and Japan could demonstrate to the world their "unwavering alliance."
Given earlier comments by Trump questioning the value of U.S. alliances, Japan was keen to seek reassurances that the new administration would continue Washington's previous policy of committing to protect the islands in the East China Sea, which are also claimed by China.
At the meeting, which lasted nearly 50 minutes, both men agreed to further strengthen the Japan-U.S. alliance. They also expressed their mutual concern over North Korea's nuclear and missile development plans, and the rising tensions in East and South China seas.
Japanese Foreign Minister Fumio Kishida echoed Abe's comments in a meeting with Mattis later on Friday, saying he wanted to further strengthen Tokyo's alliance with Washington amid the increasingly uncertain security environment in the Asia-Pacific region. A Japanese official said that at the meeting with Kishida, Mattis again touched upon the fact that the U.S. considers the Senkaku Islands as being within the scope of Article 5, and that he referred to the commitment using the same language as the previous Obama administration.
Mattis spent two days in South Korea prior to his visit to Japan. He used the trip to the peninsula to reassure the South Koreans that the U.S. was sticking to its defense commitments to the region. After talks with his South Korean counterpart, Han Min-koo, Mattis said, "Any attack on the United States or our allies will be defeated, and any use of nuclear weapons would be met with a response that would be effective and overwhelming."
In the meeting in South Korea, the two sides agreed to deploy and operate the Terminal High Altitude Area Defense (THAAD) missile defense system there this year to counter the threat from the North.
This is the first overseas tour by a senior Trump administration official, and with Secretary of State Rex Tillerson, a former Exxon Mobil CEO, short on foreign policy experience, Mattis is expected to take a leading role in Asian diplomacy.
"Mattis repeated throughout the meetings the significance of visiting Japan during the transition period in the U.S.," a Japanese official said. "I think that is the message the Trump administration is sending to Japan," he added.