'No legislative oversight'
The lawsuit claimed the October 2009 military accord was invalid because it was signed by the government of President Alvaro Uribe without prior discussion in Congress, as mandated by the constitution.
The military pact, part of a joint effort to counter drug trafficking and insurgencies, has been denounced by neighbouring Venezuela as US interference in the region, raising tensions between Bogota and Caracas.
Opponents also accuse Uribe of ignoring the advice of the State Council - the highest court on administrative matters - which also urged that the congress take up the agreement before it was signed.
The Uribe administration deemed the State Council's opinion non-binding, and said the accord was not new but merely an extension of a 1974 military pact with the United States, and as such required no legislative oversight, government officials said.