A Foreign Ministry communique says the South American country rejects "acts of espionage that violate the rights and privacy of persons and international conventions."
Brazil's O Globo newspaper reported Tuesday that citizens of Colombia, Mexico and other countries were among the targets of a massive National Security Agency operation to secretly gather information about phone calls and Internet communications worldwide. The reports were based on information provided by NSA leaker Edward Snowden.
The Colombian communique of Tuesday night expressed concern and said the government will ask the U.S. to explain, though it did not give details.
Colombia is one of the United States' closest allies in Latin America.