Pompeo discussed the matter in a phone call with new Japanese Foreign Minister Toshimitsu Motegi as he congratulated his counterpart on the new position and reaffirmed the strength of the bilateral alliance, according to the State Department.
"Secretary Pompeo emphasized the need for constructive dialogue between Japan and the Republic of Korea and for cooperating with partners and allies to ensure a free and open future for the Indo-Pacific," department spokeswoman Morgan Ortagus said in a statement. Pompeo also "reiterated the shared goal of final and fully verified denuclearization of North Korea," she said.
Washington has expressed concern that the strained relations between Seoul and Tokyo will hurt trilateral cooperation against North Korea's nuclear threats and China's military rise.
Japan imposed export controls against South Korea in July in apparent retaliation for a South Korean court ruling that ordered Japanese firms to compensate Koreans for their forced labor during Tokyo's 1910-45 colonial rule of the Korean Peninsula.
Tensions grew with Japan's removal of South Korea from a list of trusted trading partners and Seoul's decision to withdraw from a military intelligence-sharing pact with Tokyo.
In a bid to help resolve the dispute, Pompeo held a three-way meeting with South Korean Foreign Minister Kang Kyung-wha and then Japanese Foreign Minister Taro Kono in Bangkok in August, but the talks produced no tangible outcome.
Ortagus said Pompeo and Motegi also spoke about the need to ensure safe transit in the Strait of Hormuz off the coast of Iran.
The US has sought to increase international participation in a maritime coalition tasked with safeguarding the commercial waterway amid heightened tensions between Washington and Tehran. (Yonhap)