Indonesian government officials and separatist rebels from the province of Aceh have started a new round of peace talks in the Finnish capital Helsinki.
Gam has called on Jakarta to withdraw troops from Aceh
The talks are aimed at ending the 30-year conflict in Aceh in which at least 10,000 people have died.
Last week, the government lifted a year-old state of emergency in Aceh, saying the move would help post-tsunami reconstruction work there.
Aceh bore the brunt of the 26 December tsunami which killed up to 165,000.
One of the key issues to be discussed at this fourth round of talks will be security.
In the wake of the tsunami disaster, the Indonesian military and Free Aceh Movement (Gam) rebels announced an informal ceasefire, but there have since been reports of sporadic violence.
"This time we're going to visit the hardcore issues, and the security arrangements will be the main subject," the Free Aceh Movement (Gam)'s Stockholm-based spokesman Bakhtiar Abdullah told AFP news agency.
ACEH: ESSENTIAL FACTS
Located on the northern tip of Sumatra island
Population of 4.3m people
Rich fuel resources, including oil and natural gas
Gam rebels have been fighting for an independent state
The other key issue looks set to be political representation in the province.
At the last round of talks in April, Gam proposed changes to electoral laws that stipulate parties must be nationally based. Unless the law is changed, any Aceh-based political group will not be able to contest in any national or local polls.
But the government appeared downbeat on this proposal ahead of Thursday's talks.
"The government of Indonesia... can only fulfil and give promises to something that is allowable under our constitution. However, it's not allowable under our constitution," Information Minister Sofyan Djalil told Reuters news agency upon his arrival in Helsinki.
"Of course for the government of Indonesia it is very difficult to compromise on that issue."
On Tuesday, Acehnese civilian figures ended a two-day meeting with the province's rebel leaders in Sweden, giving their support to both them and the Indonesian government to press on with the talks, the Jakarta Post newspaper reports.
The two sides reopened peace talks in January, after the last set of talks broke down in May 2003.