By David Brunnstrom
WASHINGTON (Reuters) - The United States appealed to Japan and South Korea on Tuesday to work urgently to reduce the tensions between them, saying its two main allies in Asia could not afford to let their troubled history interfere with ensuring regional security.
"There is an urgent need to show prudence and restraint in dealing with difficult historical issues. It is important to handle them in a way that promotes healing," Washington's top diplomat for the East Asian region, Daniel Russel, said in prepared testimony for a U.S. Senate hearing.
Russel, the assistant secretary of state for East Asian and Pacific affairs, said strategic cooperation between the United States, Japan and South Korea was essential for future security in Northeast Asia, given the threat posed by North Korea and other "regional uncertainties," a reference to concerns about an increasingly assertive China.
"No one can afford to allow the burdens of history to prevent us from building a secure future," Russel said.
Russel's testimony came a day after nationalist politicians in Japan urged Tokyo to revise a 1993 apology over Asian women forced to serve in wartime brothels, saying accounts that tens of thousands of women were forcibly recruited were a "total lie".
Any revision to the landmark apology made by then-Chief Cabinet Secretary Yohei Kono would incense China and South Korea, from where most of the "comfort women" were drawn.
Both accuse Japan of failing to atone fully for aggression before and during World War Two.
Russel told the Senate hearing it was a diplomatic priority for the United States that tensions between the two Asian neighbors be reduced - and quickly.
"Both Japan and the Republic of Korea need to make respective efforts to help create a more conducive and positive climate," he said.
Senator Ben Cardin, chair of the East Asia subcommittee of the Senate Foreign Relations Committee at which Russel spoke, said the issue needed to be given very high priority, not least because China seemed to be attempting to take advantage.
"One of my concerns is that it looks like China is trying to increase the wedge between Japan and the Republic of Korea and to establish a closer relationship with the Republic of Korea to the detriment of Japan," he said.
Michael Auslin of the American Enterprise Institute think tank told the hearing that relations between Tokyo and Seoul were now so bad they barely spoke to each other and they appeared to be getting worse, to the detriment of the security alliance.
"Washington should be doing much more behind closed doors to make clear that our patience is not infinite, and that we cannot be as effective as we want to be if we cannot work in a trilateral fashion with our most important allies in Asia."
Tokyo's ties with Seoul have been frayed by a territorial row over small islands and the legacy of Japan's 1910-1945 colonization of the Korean peninsula - including the question of compensation and an apology to the comfort women.
The Japanese government of Prime Minister Shinzo Abe wants to bolster the military and be less apologetic about the past. It has said it will set up a team to review the testimony of South Korean comfort women, but officials have been careful to avoid any mention of revising or watering down the apology.
The 1993 apology recognized the involvement of military authorities in the brothel system and apologized for the women's suffering. It was based in part on the testimony of 16 South Korean women, their identities kept anonymous in line with a Japanese government pledge.
On Saturday, South Korean President Park Geun-hye urged Japan to stop denying the past "and write a new history of truth and reconciliation so that we can walk together towards cooperation, peace and co-prosperity."
(Reporting by David Brunnstrom; Editing by Jim Loney, Jonathan Oatis and Ken Wills)