Burmese President Thein Sein says his government is committed to moving the country towards a healthy democracy after decades of military rule.

Thein Sein commented Monday during a formal state dinner in Singapore, and again in a newspaper interview in the city-state's Straits Times newspaper.

Burma's military-backed civilian government has undertaken a series of dramatic political reforms since taking power last March, including the release of hundreds of political prisoners, the holding of peace talks with ethnic rebels and the allowance of greater press freedoms.

Armed ethnic groups are cautiously optimistic after recent talks with the new Burmese government. But a senior commander of the Karen ethnic militia says that decades of conflict cannot be solved overnight.

“We have a ceasefire with the Burmese government, but we cannot trust them 100 percent. We have to be careful.''

The Karen National Liberation Army is marking the 63rd anniversary of the Karen revolution in the northern state. The commander of the Karen National Union, Colonel Nerda Mya, told reporters Tuesday that although his troops have withdrawn, the agreement with the central government is preliminary and requires further negotiations.

“We've been fighting for 63 years. I think if they agree to talk with us, we are happy for peace negotiations and resolving our problems on the negotiating table, but that's what we've always wanted. But if we cannot talk to them and they only reject our proposals, then we have to stand up for our rights.''

Burma's ethnic groups have expressed hope that April by-elections will bring more democracy to the country emerging from decades of military rule.

The United Nations special envoy on human rights in Burma, Tomas Ojea Quintana, starts a six-day visit to the country Tuesday to assess the progress of its democratic reforms.

The Burmese president arrived in Singapore Sunday, accompanied by a delegation of business leaders and economic ministers.

The two sides signed an economic agreement Monday that calls for Singapore to offer technical and vocational education to help Burma train people in such areas as economic planning and urban development.

Burma's economy has largely ground to a halt after decades of mismanagement by the military junta, as well as international sanctions against the junta over its poor human rights record.