WASHINGTON — The United States appealed Tuesday to its closest Asian allies, Japan and South Korea, to improve their strained relations, saying there's an urgent need to show restraint on "difficult historical issues."
Assistant Secretary of State Daniel Russel's comments reflect growing angst in Washington over the widening gulf between Tokyo and Seoul over Japan's attitude to its wartime and imperial past.
Deepening that standoff, the nationalist government of Japanese Prime Minister Shinzo Abe recently announced it is reviewing evidence on which a landmark 1993 apology over forced prostitution during World War II was based. South Korea's President Park Geun-hye has warned that a review of the apology would only isolate Japan.
In congressional testimony, Russel said dedicated efforts by both parties are needed to calm the tensions. He didn't apportion blame for the strained relations but said historical issues should be handled "in a way that promotes healing."
Although numbers vary, some historians say as many as 200,000 women from across Asia, most of them Koreans, were forced to serve as sex slaves, called "comfort women" in Japan, for front-line soldiers during World War II.
Japanese nationalists have long insisted that women in wartime brothels were voluntary prostitutes, not sex slaves, and that Japan has been unfairly criticized for a practice they say is common in any country at war.
The dispute between Japan and South Korea has constrained U.S.-backed efforts to forge closer security cooperation among them. The two nations together host nearly 80,000 American forces. Notwithstanding the animosity, both are liberal democracies and face a common threat from an unpredictable North Korea.
"It is very much a diplomatic priority for the United States that the friction and the tension between these two extraordinarily close friends and allies of the United States be reduced, and be reduced quickly," Russel, the top U.S. diplomat for East Asia, told a Senate foreign relations subcommittee that oversees U.S. policy toward the region.
"Both Japan and the Republic of Korea need to make respective efforts to help create a more conducive and positive climate."
Sen. Ben Cardin, the panel's Democratic chairman, said the Japanese prime minister's rhetoric on historical issues "is increasingly concerning to many." He also said China appears to be trying to increase "the wedge" between Japan and South Korea to establish a closer relationship with Seoul to the detriment of Tokyo.
Michael Auslin, an Asian studies expert at the American Enterprise Institute think tank in Washington, told the panel that Japan-South Korea tensions are at their highest level in decades and seem to be worsening.
He said that makes it difficult to "optimize" the U.S. security presence in Northeast Asia, and there appears no prospect of the two nations setting aside their differences soon.