President Uribe's deal with the US has caused concern in the region
Colombian opposition groups have reacted angrily after details of a controversial military deal with the US were made public.
Under the 10-year deal, the US military will not only have access to military bases, but also be able to use major international civilian airports.
US personnel and defence contractors will also enjoy diplomatic immunity.
President Alvaro Uribe says the agreement will help rid Colombia of drugs gangs and left-wing rebel groups.
But leading opposition senator Gustavo Petro, of the left-wing PDA party, said the deal amounted to a virtual US occupation of Colombia.
They reveal that the US military will have access to seven Colombian army, navy and air force bases and also be able to use civilian airports under conditions that have still not been made clear.
The deal has led to a worsening of already strained ties between Colombia and Venezuela.
