Both sides now blame each other for the military build-up which may pit 3,000 to 10,000 fighters against 30,000 government troops.
"In the next several days, the president will take the official decision in a presidential decree marking the start of integrated operations," said chief security minister Susilo
Bambang Yudhoyono to reporters.
"Up to now, what has been stated by GAM, officially or unofficially, did not answer what the Indonesian government wanted."
But a spokesman for the fighters in Stockholm said they had not
received a direct answer to a message sent to Jakarta on Saturday, and that GAM was "encouraged" that any assault had, apparently, been postponed until at least Wednesday.
There may be clashes between
GAM fighters and troops
"Now there is a bit more space for the international community to find out some way for this attack to be cancelled," Muhammad Nur, the spokesman said, adding that GAM could now only wait for Jakarta to take the next step to solve the crisis.
"We are open for negotiations. But if they attack, we cannot stand still," he said.
The 26 year conflict in Indonesia's resource-rich westernmost province has killed more than 10,000 people, most of them civilians.
It threatens the stability which Indonesia desperately needs to lure back investors after five years of economic crisis and bouts of political turmoil.
There was optimism when GAM and the government agreed to a 9 December peace deal brokered by the Geneva-based Henry Dunant Centre (HDC).
Bringing an initial drop in violence, it called on GAM to begin laying down arms and government troops to gradually withdraw to defensive positions. Both sides blamed each other for not living up to their end of the accord.
Peace efforts expire
Last-ditch efforts to salvage the pact suffered a blow earlier on Monday when a team of some 50 mostly Thai and Filipino peace monitors pulled out of Aceh's capital, Banda Aceh -- 1,700 km (1,060 miles) northwest of Jakarta.
|Students in Banda Aceh protesting|
against military action in the region
The monitors' withdrawal came as last minute talks continued in Sweden between GAM leaders and HDC representatives, in a final attempt to prevent conflict.
Yudhoyono said parliament would be consulted, probably after German Chancellor Gerhard Schroeder ends a visit to Indonesia on Wednesday.
Scores of police patrolled Banda Aceh where some businesses and markets were closed and around 200 students gathered in the main street to protest at plans for military action on Monday.
Several thousand troops embarked for Aceh last week to reinforce tens of thousands already there, and the military has warned there would be no half measures in any attack.
Conflict in Aceh may hurt Megawati's efforts to lure investors but analysts say she has broad domestic support for a tough line.