Analysts say a worsening territorial dispute between Japan and South Korea could jeopardize U.S. policy in the Asia-Pacific region.

The dispute escalated last week, when South Korean President Lee Myung-bak visited a group of uninhabited islands claimed by both countries, prompting Japan to recall its ambassador. It was the first visit by a South Korean president to the islands, called Dokdo in South Korea and Takeshima in Japan.

Seoul and Tokyo have long had rocky relations, due in part to anti-Japanese sentiment left over from Japan's harsh colonial rule of the Korean peninsula from 1910 to 1945.

State Department spokesperson Victoria Nuland on Monday encouraged South Korea and Japan to repair ties, but said Washington did not take sides in the dispute.

David Fouse of the Hawaii-based Asia-Pacific Center for Security Studies tells VOA a lack of cooperation between the two key U.S. allies puts at risk a key element of the Obama administration's pivot toward Asia.

“(Washington is) looking for all of our partners and allies to do a little more in terms of maintaining the global commons and communications, (and) contributing more to the regional security framework. And if our two partners aren't able to cooperate, I think it undermines that goal.”

In June, South Korea postponed the signing of what would have been its first military accord with Japan since 1945. Security analyst Jonathan Blaxland of Australian National University says it was largely South Korean domestic opposition that led to the cancellation of the intelligence sharing agreement.

But Blaxland tells VOA that while the most recent dispute is a serious issue, it is likely to soon pass.

“What we're seeing is a potentially significant and useful political distraction for President Lee at the moment, given problems with his brother and other connections with corruption allegations. So beating the nationalist can is actually a pretty convenient thing to do at the moment.”

He says the situation could also change following South Korean elections set for December in which President Lee is not eligible to run.

But for now, the situation does not appear to be improving. Japanese media reports said Monday that Tokyo is considering suspending bilateral talks set for next month at a regional summit in Russia. Japan has also said it could take up the territorial dispute with the International Court of Justice.

Fouse points out that the one party that could benefit from ongoing tension between Seoul and Tokyo is China, which would welcome the scuttling of any security cooperation between the two.