Speaking at separate news conferences, the two sides and their Finnish mediator voiced confidence on Wednesday that the next round would lead to an end to the civil conflict in the northern Indonesian province in which 12,000 people have died.
"We have discussed the same issues for four rounds, over the past five months, with consistency," Hamid Awaluddin, the Indonesian justice minister and chief negotiator, said after six days of talks in Helsinki covering security, political and economic issues.
"The longer we discuss the more friendship we get ... having had this we are optimistic to be in a position to get a final agreement," he said.
The fifth round of talks will be held in Helsinki from 12 July for about a week under the auspices of former Finnish president Martti Ahtisaari.
"I have a date set aside in August," Ahtisaari said, alluding to the prospect of a signing ceremony for a memorandum of understanding, a month after negotiators seal a deal.
Ahtisaari's Centre for Crisis Management has been asked to prepare a document that summarises the agreed points over the four rounds of talks that could form the basis of an agreement.
Former Finnish president Martti
Ahtisaari is the chief mediator
"The spirit of cooperation is there and both sides have made significant compromises and concessions. This has brought us closer towards a final settlement," said Bakhtiar Abdullah, spokesman for the Free Aceh Movement (GAM).
The Indonesian government and legislators will study GAM documents, containing the new positions of both sides on issues including political participation, ceasefire and human rights.
Peace talks were revived after the 26 December tsunami killed up to 160,000 people in Aceh, on the northern tip of Sumatra.
The GAM has fought for independence for Aceh, which is rich in oil, gas and metals, since 1976. Neither party is discussing independence at the peace talks.
But officials said both sides had reached an understanding that the EU would monitor any peace agreement. EU peacekeeping experts joined the talks on Monday.
The Association of Southeast Asian Nations (ASEAN) is also being looked to for peace monitors. Unarmed monitors would have to oversee the surrender of weapons by GAM rebels and the withdrawal of Indonesian troops.
A peace deal would smooth the way for Aceh's reconstruction after the tsunami, as billions of aid dollars pour into the province. The EU has pledged $133.8m in aid to nations hit by the Indian Ocean disaster.
Former US president Bill Clinton, the UN's envoy for tsunami relief, told reporters in Aceh on Monday that a complete recovery required an end to the civil conflict in the province.