The United States defence secretary, William Cohen, has promised more US help for the Colombian armed forces to enable them to modernise and be better able to combat what he described as "narco-trafficking and narco-terrorism".

Mr Cohen was speaking in Bogota, where he's attending a meeting of defence ministers from the Americas, which is discussing the present and future role of the military in the continent.

Correspondents say the US is increasingly concerned about the inability of Colombia's poorly trained and equipped army to combat left-wing rebels, who are often in league with drug producers.

In another development, the army rejected as preposterous a statement by left-wing rebels that the armed forces were planning to assassinate one of their leaders and so sabotage peace talks.