Defense Minister Itsunori Onodera said he reached an agreement Sunday with his U.S. and South Korean counterparts to work in tandem to urge North Korea to take concrete steps toward denuclearization, less than 10 days before a planned summit between U.S. President Donald Trump and North Korean leader Kim Jong Un.

But Onodera shied away from specifying what the three allies concluded about the strategy of using pressure against the North during his hour-long talk with U.S. Defense Secretary Jim Mattis and South Korean Defense Minister Song Young-moo in Singapore.

The three "agreed to closely cooperate to compel North Korea to take concrete steps" in a complete, verifiable and irreversible manner, Onodera told reporters following the meeting with Mattis and Song.