Simon Bowden: Securing a peace deal is likely to be a delicate business

In a joint statement, both sides acknowledged they faced a long and arduous process to achieve a settlement.

The talks took place in an area controlled by the country's largest and oldest rebel group, the Revolutionary Armed Forces of Colombia (FARC).

Quill Lawrence: Short statement after talks

One of the rebels' main demands is the dismantling of paramilitary groups, which are believed to receive support from the armed forces.

The talks in the remote Amazon town of San Vicente del Caguan are intended to agree upon an agenda and venue for full-fledged negotiations between FARC and government representatives later this year.

More than 1,000 international observers, journalists and guests were joined by hundreds of policemen and heavily-armed guerrillas to witness the historic occasion.

However, police say more than 100 civilians have been killed in a fresh spate of attacks by right-wing paramilitary groups opposed to the rebels.

Police blamed the killings in the north of the country on an illegal group called the United Self-Defence of Colombia which had called a truce over Christmas.

The most recent incident was in the northern Colombian town of San Pablo, where 14 people were taken from their homes and shot dead.

Meanwhile, the authorities in Bogota say the Revolutionary Armed Forces of Colombia have released a Canadian engineer, Norbert Reinhart, taken hostage in October.

A German national, Osmar Broda, kidnapped while on holiday last month, was also freed by the country's second largest rebel group, the National Liberation Army. It is not certain whether any ransom had been paid.

Army pull-out

Mr Pastrana has made peace almost the only issue in his presidency, responding to overwhelming support among the population for an end to the war, which has claimed over 35,000 lives in the last decade.

In November, Mr Pastrana met the guerrillas' demand that he pull the army and police out of an area of jungle about the size of Switzerland so that talks could begin.

Locally-appointed civilians now keep order in the zone but the guerrillas have armed roadblocks at all entry points.

The FARC is the most successful of Colombia's leftist guerrilla groups, numbering about 15,000 and controlling an estimated 40% of the countryside.

They are demanding political and social change in the country as well as land redistribution.