Admiral Thomas B. Fargo told a news conference "there have been no deadlines or datelines established" but that two months was probably long enough for the main military aid effort.

"My observation here is that we are pretty much past the immediate relief phase and we're rapidly moving towards rehabilitation and reconstruction.

"We will start right now transferring functions to the appropriate host nation and international organisations," he said.

Pressed on when US forces would leave, Fargo said: "What history has shown us -- relief efforts in (typhoon-hit) Bangladesh in 1991 called Operation Sea Angel -- the military effort was about 60 days in length. That's probably a pretty good benchmark," he said.

"That's not to say that we won't contribute to unique capabilities as requested by the host nation past that point, we certainly will," he said, adding that the United States was "committed to what clearly will be a long-term recovery effort".

Fargo was speaking in the wake of a controversy which has dogged the presence of foreign troops carrying out relief work in Aceh, where more than 166,000 people were killed by the December 26 tsunami.

On Sunday, Indonesian Defence Minister Juwono Sudarsono said an earlier demand by the country's vice president, Yusuf Kalla, that overseas troops quit within three months or "the sooner the better" was not a deadline.

Indonesia, the world's most populous Muslim nation, has been sensitive to the presence of US and other Western forces on its soil, particularly in Aceh where it has long waged a war against separatist rebels.

Fargo said the tsunami disaster "tested" the relationship between the United States and affected countries and the result was "very successful cooperation".

In response to a question, he said he believed the image of US military forces in the region was "excellent", but attributed that not only to the relief effort.

"I've been out here five and a half years... and I've felt that our image out here has been excellent throughout that period of time.

"We've got a great number of good friends, we work together on a regular basis, and certainly the partnerships that have been developed out here over many years are key to the ability of this region to respond effectively to this tragedy.

"What you've seen over the past few weeks is these relationships have been tested if you will. The results of that test has been very successful cooperation," he said.

Fargo is on a seven-day visit to the tsunami-hit region and was in Thailand, Indonesia and Sri Lanka before visiting Malaysia. He was due to visit Singapore later Thursday before returning to Hawaii.