Canberra – East Timor Foreign Minister Jose Ramos Horta has demanded Australia halt development of massive natural gas fields in the Timor Sea until a dispute over their ownership is settled.

Ramos Horta said Australia should not exploit resources potentially worth billions of dollars before a treaty detailing how they will be distributed is finalised.

"We would hope Australia and everybody else with a stake in the region, bearing in mind the claims by our side, would refrain from any new actions that would complicate the issue," he told a function.

Ramos Horta, joint winner of the Nobel Peace Prize in 1996, also called for Canberra to speed up negotiations on the maritime border between Australia and East Timor – the key to who receives the bulk of the gas revenue. East Timor regards proceeds from the gas fields as the only way the fledgling nation can overcome its dependence on aid following independence from Indonesia.

Australia withdrew from the International Tribunal for the Law of the Sea, in March 2002 in what the East Timorese government described at the time as a "hostile act" designed to stop it receiving its fair share from the gasfields.

The most hotly disputed part of the border concerns the Greater Sunrise field, most of which lies outside an area covered by a joint development treaty between Australia and East Timor.

Instead, the bulk of the field is covered by an interim deal known as the International Unitisation Agreement, which gives 90 percent of revenues to Australia.

Some East Timorese fear Australia will allow the border talks to drag on for decades so that by the time the issue is settled the gas fields will be virtually empty.

Australia claimed 80 percent of Greater Sunrise under the terms of a maritime treaty signed with Indonesia when it occupied East Timor. But after East Timor became independent, Dili claimed a far greater part of the field lay within its maritime boundaries.