Japan said Thursday that its alliance with the United States has served as a deterrent in a territorial dispute between Tokyo and a rising China as it called for calm in the row.

Washington has stated that it takes no position on the disputed islands, known as the Senkaku in Japanese and the Diaoyu in Chinese, but has made clear that its security treaty with Japan covers all areas under Tokyo's control.

The United States "has been saying that they do not take a position on the sovereignty issue but have always stated that US-Japan security arrangements would cover those islands," said Ichiro Fujisaki, Japan's ambassador to Washington.

"I think that constitutes an important deterrence," he said at the Brookings Institution think tank.

Tensions have soared in recent months as rival nationalist groups sailed to stake their claims to the remote and potentially resource-rich area. Japan has moved to nationalize the islands from a private buyer, in what it called a bid to preempt a similar attempt by Tokyo's firebrand local governor.

Fujisaki downplayed speculation that the row and a separate island dispute with South Korea would flare into full-blown conflict, saying: "That's not going to happen, that should not happen."

"This is not started by us -- by Japan -- and we have a good historical and legal position on these," he said of the territorial disputes.

"However, our position is very clear -- we are not going to raise tension and try to take it up emotionally. We would like to calmly deal with this," he added.

The rows have spread to global economic policy, with China shunning annual IMF and World Bank meetings underway in Tokyo.

However, Fujisaki credited China with making progress in recent weeks in controlling anti-Japanese protests.