Colombia's President Alvaro Uribe has said he is ready to hold peace talks with Colombia's Farc rebels, but that strict conditions would have to be met.

He called for "a halt to all criminal activities" and a verifiable ceasefire.

"We believe in peace, but we won't allow new tricks," he said, reiterating his resolve to fight the Farc.

On Sunday, the rebel group dropped its demand for a demilitarised area to be set up as a precondition for talks on a swap of rebel hostages for prisoners.

Farc has launched a new offensive, including a campaign of bomb attacks in cities, since suffering a series of defeats in 2008 - though it has recently suggested it may be willing to pursue "political alternatives".

The government, meanwhile, has been pursuing a strategy of pressuring individual rebel units into abandoning the 45-year civil conflict rather than engaging in high-level talks with the leadership.

Now Mr Uribe has said he is willing to talk, but on tough conditions.

"Peace has its demands. The moment a new process begins there must be a clear sign, a halt to all criminal activities by the groups who want to engage in the process, with verification," he said.

'Democratic values'

Without the verification, he said, "we risk talking peace in a language that obfuscates terrorism".

The rebels have pursued their violent campaign despite a series of setbacks

He reiterated his government's resolve to fight terrorism "in an all-out effort and in full respect of democratic values".

Mr Uribe has repeatedly been accused of ignoring human rights in his determination to crush the rebels.

The Farc, meanwhile, has relaxed its insistence on securing an extensive demilitarised zone in Colombia's south-west as a precondition for talks over exchanging 22 prominent hostages for hundreds of jailed rebels.

There were several failed attempts at peace negotiations with Mr Uribe's predecessor, Andres Pastrana, but since Mr Uribe came to power in 2002 such initiatives have been largely abandoned.