WASHINGTON -- Defense Secretary Jim Mattis and Japanese Defense Minister Itsunori Onodera discussed North Korea's Sept. 2 test of a nuclear device in a telephone conversation yesterday, chief Pentagon spokesperson Dana W. White said.

Mattis and Onodera both condemned the test as a destabilizing provocation that threatens both regional and global security, White said in a statement summarizing the call.

Ironclad Commitment

"Secretary Mattis underscored that the United States' commitment to defend Japan, including the U.S. extended deterrence commitment, remains ironclad," she added.

The secretary also underscored that the United States would work with Japan to enhance its ballistic missile defense capabilities, White said, and the defense leaders confirmed their intent to continue working trilaterally with South Korea to strengthen deterrence and to maintain the peace and security of Northeast Asia.

Mattis and Onodera also spoke by phone Aug. 30 after North Korea's Aug. 28 launch of a ballistic missile over Japan.