Prime Minister Shinzo Abe and Adm. Harry Harris, commander of U.S. Pacific Command, agreed Thursday to maintain "maximum pressure" on North Korea, the day before a landmark inter-Korea summit.

Abe and Harris affirmed during their meeting the need for Pyongyang to abandon all of its weapons of mass destruction and every kind of ballistic missile programs in a "complete, verifiable and irreversible" manner, according to the Foreign Ministry.

"The multilateral relationship between Japan, the United States, the Republic of Korea and other friends and partners in the region to keep the pressure campaign active on North Korea, I believe, is important to regional stability throughout the Indo-Pacific," Harris said at the outset of the talks.

The president's nominee for secretary of state, Mike Pompeo, asked for Harris to be sent to South Korea, though he had previously been the president's pick for ambassador to Australia, a Trump administration official said Tuesday.

The ambassadorship to South Korea lies vacant ahead of a summit between Trump and North Korean leader Kim Jong Un — the first ever between sitting U.S. and North Korean leaders — expected to take place by early June.

"I want to express my heartfelt appreciation for your contribution to strengthening the Japan-U.S. alliance, and ask for your support in continuing to do so," Abe said.

Harris, who was born in Japan to a serviceman in the U.S. Navy and a Japanese mother, became the first Japanese-American to serve as commander of Pacific Command in May 2015.