The Colombian President, Andres Pastrana, has said he wants to improve relations with the United States by eliminating drug-trafficking as a source of tension between them.

Mr Pastrana made the comments on arrival in Washington for the first state visit by a Colombian president since 1975.

He also said he would be seeking Washington's support to end Colombia's civil conflict.

The BBC State Department correspondent says despite the improvement in ties, Mr Pastrana still needs to show concrete efforts in tackling the drug cartels to guarantee US backing.

Some members of Congress oppose his decision to demilitarise large areas of Colombia, arguing that this will hamper the fight against drug producers.