The White House says President Barack Obama and Japanese Prime Minister Shinzo Abe (shin-zoh ah-bay) are consulting on a response to North Korea's test this week of a nuclear device at a remote underground site.

Obama has called the test a "provocation." He and Abe spoke Wednesday and pledged to work together to seek action against North Korea by the U.N. Security Council. They also agreed to cooperate on measures aimed at impeding North Korea's nuclear and ballistic missile programs.

North Korea's official news agency said the test was conducted to counter what it called "ferocious" U.S. hostility toward the regime.

Obama reiterated to Abe the U.S. commitment to defending Japan, including by nuclear means.

He said he looked forward to further talks when Abe visits Washington later this month.