Canberra – Australia will leave around 100 peacekeeping troops in East Timor if the United Nations extends its mission in the world's newest country for another year as expected, the government said on Wednesday.

The UN Security Council is due to consider this week a new mission in Southeast Asia's poorest nation to replace the existing peacekeeping operation that ends on May 20.

"Our force size will probably be reduced to about 100," a spokeswoman for Australian Defence Minister Robert Hill said.

"Maybe some engineers, maybe some headquarters people and some logistics support, and I think we will also provide some of the military liaison people." There are now about 1,750 UN troops and military observers in the tiny country, of which around 400 are Australian, down from a peak of 5,000 Australian troops in late 1999 when the country led a multinational peace operation into East Timor.

More than 1,000 people died in fighting in 1999 when East Timor voted for independence from Indonesia, with most deaths blamed on pro-Jakarta militias backed by elements of the Indonesian military.

UN Secretary-General Kofi Annan has suggested keeping a force of 310 soldiers and an intervention force of 125 police to patrol the border separating East Timor from the Indonesian province of West Timor, as well as some civilian staff.

Many East Timorese fear the re-emergence of militias. "We haven't seen signs of the militia for a long time. We don't think that East Timor's challenges are external security challenge," Hill's spokeswoman said.

"Indonesia is being supportive and helpful. The biggest challenges to East Timor in terms of security will be law and order. That includes things like customs and border issues and people movements but not an armed threat."

East Timor is one of the world's poorest nations with a a population of about 700,000 and receives $150 million a year in aid from nations led by Australia, Japan and the United States.