Talks between the Sri Lankan government and the rebel Liberation Tigers of Tamil Eelam (LTTE) have begun near Geneva.
The meeting, organised by Norway, is the first between the two sides for nearly three years, and takes place amid escalating violence in Sri Lanka.
Discussions are expected to focus on the implementation and the strengthening of a ceasefire agreement, brokered by Norway in 2002.
There were some positive signs ahead of the talks including an exchange of prisoners between the two sides last week.
Martin Stürzinger, advisor for peace building at the Swiss embassy in Colombo, told swissinfo that Switzerland's role as host of the talks would be organisational.
"Switzerland supports the peace process under Norwegian facilitation," said Stürzinger. "This offer was made in the framework of the Swiss commitment to support peace, human rights and development in Sri Lanka."
According to the Sri Lankan media, the meeting is due to take place at the Bossey Ecumenical Institute at Celigny, around 20km from Geneva.
In a statement ahead of the talks, the Swiss foreign ministry said it would do its utmost to ensure that they took place in an environment that was conducive to reaching a mutually acceptable solution.
The statement also welcomed the reduction in the number of ceasefire violations since the talks were announced on January 25, and called on all parties to do everything in their power to ensure that discussions could start in a constructive atmosphere.
Observers say the Swiss-hosted talks are likely to be one of the last chances to avert a slide back into civil war.
Norwegian facilitator Erik Solheim, who will be at the talks, has called the meeting a "small but very significant step" in getting the peace process back on track.
Top LTTE officials say the Tamils are committed to the ceasefire, but have implied that the talks could decide whether there is a return to civil war.
Martin Stürzinger described the timing of the talks as crucial. "Soon after the presidential election in November tension mounted to a very high degree, so I think it's crucial to have the talks now."
He added that "[a]n optimistic outcome would be that the tension further decreases and the parties agree to a date and a venue for a next round of talks".
Sri Lanka has been beset by two decades of conflict between the Tamil Tigers and majority Sinhalese government, over Tamil demands for an autonomous state in the north and east of the country.
The president, Mahinda Rajapakse, reiterated earlier this month that he would not accept a separate state for the Tamils, but would consider sharing power.
Tensions in the north and east have increased following the election of Rajapakse and the killing of the foreign minister last year.
At least 120 people, including about 80 from the security services, have died in the upsurge of violence since the presidential election in November. Both sides have blamed each other.
swissinfo, Isobel Leybold-Johnson
The meeting will take place near Geneva from February 22-23.
It is hosted by Switzerland. The facilitator is Norway.
According to reports, the Sri Lankan government is sending a seven-member delegation. Three members have been confirmed by the government, including Health Minister Nimal Siripala de Silva, who will head the delegation.
The LTTE team is said to be headed by veteran negotiator Anton Balasingham, and includes S. P. Thamilselvan, its political head.
More than 35,000 Tamils live in Switzerland, which means Sri Lanka is of particular importance in Swiss foreign policy.
Switzerland and Germany finance a centre which advises Sri Lankan decision makers on how to resolve conflict peacefully.
Delegations from the Sri Lankan government and the LTTE have visited Switzerland to study its federal model.
Switzerland also assists with demining efforts in Sri Lanka. The ministry says this encourages the return of displaced persons, who are then more willing to support the peace process.