(ATTN: UPDATES with Japan rejecting three-way talks in last three paras)
SEOUL/WASHINGTON, July 14 (Yonhap) -- U.S. officials have expressed concern that tensions between South Korea and Japan over Tokyo's export restrictions against Seoul are not conducive to trilateral cooperation between the three countries, Seoul's deputy national security adviser said Saturday.
Kim Hyun-chong, deputy chief of Cheong Wa Dae's National Security Office, made the remark to reporters as he wrapped up a four-day visit to Washington that included meetings with top officials, such as acting White House chief of staff Mick Mulvaney, U.S. Trade Representative Robert Lighthizer and Deputy National Security Adviser Charles Kupperman.
The trip came after tensions between Seoul and Tokyo spiked as Japan toughened restrictions on exports to South Korea of key industrial materials used in semiconductors and displays in an apparent retaliatory measure in a separate row over Japan's wartime forced labor.
"I met with people in the U.S. administration, Congress and think tanks, and explained the unfairness of Japan's unilateral measure and the effects of this unfair measure have on the security situation among the South, the U.S. and Japan," Kim told reporters at Washington's Dulles International Airport.
"All the people I've met shared the understanding about the concerns over tensions between the South and Japan caused by this unilateral measure," Kim said. "That's why the State Department said it's going to do everything it can to maintain cooperation among the South, the U.S. and Japan."
Kim said, however, that U.S. officials have not talked explicitly about "mediation."
"I believe that the U.S. is going to do what it has to do if it considers cooperation among the South, the U.S. and Japan important," he said.
Japan imposed the export curbs on July 4, in an apparent retaliatory step for last year's Supreme Court rulings here that ordered Japanese firms to compensate victims of wartime forced labor.
Japan has protested the rulings, arguing that all reparation issues stemming from its 1910-45 colonization of the peninsula were settled under a 1965 government-to-government accord aimed at normalizing bilateral ties.
South Korea has refused to intercede in the civil litigation, saying it honors the democratic constitutional principle that guarantees the separation of the executive, legislative and judicial powers.
In an apparent effort to mediate between the two allies, the United States has offered high-level trilateral talks with the South and Japan to discuss the issue, but Japan has spurned the offer, citing scheduling problems, diplomatic sources said.
Sources said that the U.S. was greatly disappointed at the Japanese attitude.
"The U.S. also sees a problem with Japan even refusing a dialogue offer," a source said.