Australia expressed disappointment Friday that East Timor will resume a legal battle in the UN's highest court over a controversial oil and gas treaty between the two countries, and vowed to "strongly defend" its case.
East Timor announced this week it would press ahead with its case against Australia at the International Court of Justice (ICJ) in the Hague, after a six-month hiatus for talks failed to settle a dispute over the boundaries for vast maritime energy fields shared in the Timor Sea.
The tiny, half-island nation, which has a sluggish economy heavily dependent on oil and gas, wants the treaty signed in 2006 which determined the maritime boundaries torn up, as it claims Australia spied on ministers to gain commercial advantage.
Australia allegedly used an aid project refurbishing East Timor's cabinet offices as a front to plant listening devices to eavesdrop on deliberations about the treaty in 2004.
Australia's Attorney-General George Brandis said Friday both countries had agreed not to renegotiate the maritime boundaries while the treaty was still in effect.
"Australia remains committed to that agreement and is disappointed that Timor-Leste is attempting to re-open it," he said Friday, referring to East Timor's preferred name.
"The Australian Government believes differences between our nations are best resolved through consultation."
The treaty splits proceeds from lucrative Greater Sunrise fields 50-50 between the neighbours, despite Australia claiming the vast majority lie in its exclusive seabed.
East Timor wants the treaty nullified and the boundaries redefined to place more of the oil and gas resources within its territory, a move Australia has vowed to strongly oppose at the ICJ.
East Timor agreed this week to drop a separate ICJ challenge against Australia, in which it was demanding the return of sensitive documents related to the long-running treaty dispute.
The documents were taken by Australia's intelligence services in a 2013 raid on the office of a lawyer representing East Timor in its spying case.
Australia returned the documents last month as an act of "good faith, without acknowledgement that Australia had violated Timor-Leste's sovereign rights," Brandis said.
The 2006 treaty was signed between Canberra and Dili, several years after East Timor won independence following years of brutal Indonesian occupation.