U.S. Defense Secretary James Mattis has reaffirmed the U.S. commitment to a mutual defense treaty with Japan during a meeting with Prime Minister Shinzo Abe in Tokyo.
"Due to some of the provocations out of North Korea and other challenges that we jointly face, 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," Mattis said on February 3.
"We stand firmly, 100 percent, shoulder-to-shoulder with you and [the] Japanese people," Mattis said.
Earlier, in South Korea, Mattis said any nuclear attack by North Korea would trigger an "effective and overwhelming" response.
He said Pyongyang continues to "engage in threatening rhetoric and behavior."
Mattis is on the first overseas tour by a senior administration official, amid concerns about the direction of U.S. policy in the region under President Donald Trump.
South Korea has enjoyed U.S. security protection since the 1950-53 Korean War. Trump threatened during his election campaign to withdraw U.S. forces from South Korea and Japan if they do not step up their financial support.
Some 28,500 U.S. troops are based in South Korea to defend it against North Korea, and 47,000 in Japan.
North Korea carried out two atomic tests and a series of missile launches last year and casts a heavy security shadow over the region.
Based on reporting by AFP, AP, and CNN