Security has been tightened in Arauca for the president's stay

The president, with an 80-strong entourage of ministers and military chiefs, is to govern from an army headquarters in Arauca for three days.

The north-eastern Arauca region, on the Venezuelan border, is one of the areas worst affected by conflict between guerrillas, paramilitaries and government forces.

On the day Mr Uribe was due in the region, the main left wing rebel group - the Revolutionary Armed Forces of Colombia (FARC) - released a statement rejecting the government claims of successes against their forces.

It said the claims of thousands killed, captured or deserted in Mr Uribe's first year and were aimed at diverting attention from calls for peace talks.

Security

Last month, Mr Uribe announced what he called a policy for defence and democratic security which sets out to tackle all rebel groups and end almost 40 years of civil war in Colombia.

The president's relocation to Arauca is thought to be the first time a president has moved the government headquarters to a conflict zone.

FARC say they want peace talks - with conditions

However, it is not a first for Mr Uribe who, while governor of Antioquia moved his headquarters to Apartado during a period of unrest in the area.

A presidential spokesman said: "It's a way of demonstrating that the president can govern from any part of the country and that there aren't any no-go zones, despite problems of violence and insecurity."

Security measures have been tightened in Arauca to enable Mr Uribe to make his point.

Special vehicles and satellite communication have been sent to the region so that presidential duties can be carried out unhindered by the temporary move.

Oil protection

The first time the president visited Arauca a car bomb exploded, killing a policeman just before the presidential plane landed.

Recently the region has endured assassinations of social, political and religious leaders as well as power restrictions after pylons were knocked down by rebels.

Arauca is home to the Cano Limon oil camp, which is operated by the US multinational Occidental Petroleum.

BBC Mundo's Hector Latorre, in Bogota, said that since January about 70 members of the US special forces have been training Colombian troops in anti-terrorism operations to protect the pipeline.