U.S. State Department spokeswoman Victoria Nuland earlier used the Japanese word "Senkakus" in referring to the Diaoyu islands.

But she says the US has not taken a position in the dispute. She re-affirmed the stance during a daily briefing after being repeatedly questioned on the subject.

Already heightened tensions between China and Japan over the islands have flared in recent days. On Aug. 15, 14 Chinese nationals were detained by Japan after landing on the Diaoyu Islands to claim China's sovereignty.

China says this action was illegal. It maintains that the Islands have been inherent Chinese territory since ancient times. It has urged Japan to refrain from actions that might violate China's territorial sovereignty and use dialogue and negotiation to solve the ongoing dispute.