Australia's support for an end to the UN mission in East Timor reflected a desire to improve relations with Indonesia and extend its influence in the former Portuguese territory, a US thinktank says.

An analysis of Australia's support for an end to the United Nations operation which expires on June 30, was carried out by Stratfor, the private sector intelligence group.

Stratfor said ending the UN mission would also force East Timor to look to Australia for its security. And it would make it all the more difficult for Dili to resist Australia's firm stand on settlement of the sea boundary issue and allocation of energy reserves in the area.

Australia has backed the US in opposing extension of the UN mandate on grounds that Indonesian forces and their militia surrogates no longer pose a security threat.

UN Secretary General Kofi Annan wants the mission to continue, although with international troops numbers reduced from 472 to 179. Australia has about 100 troops serving under the UN banner in East Timor plus another 30 engaged in bilateral defence cooperation.

Stratfor said Canberra's support for the US position reflected Australia's desire to increase political leverage on Dili by forcing East Timor to look to Australia rather than the UN for its security.

"The US and Australian calls for an end to the peacekeeping mission can be seen as an effort to improve ties with Indonesia, which views the peacekeepers' ongoing presence as an affront to its intentions in the region," it said.

"Indonesia's role as the recruiting and operational centre for Southeast Asian Islamist militancy means that Washington and Canberra would like good relations with Jakarta in order to gain its cooperation in anti-terrorism efforts.

"However, Australia also is motivated by its desire to establish a protectorate in East Timor in order to ensure compliance with Australian interests in the region."

Stratfor said by reducing the UN role in guaranteeing East Timor's security, Australia could fill the void by offering bilateral security arrangements and increasing the presence of Australian police and military forces, as it had done in the Solomon Islands, Fiji and Papua New Guinea.

Even if the UN extended the mission, ensuing troop reductions would most likely open the door for an increased role for Australian forces and a decrease in Dili's ability to resist Australia's prerogative, it said.