WASHINGTON (CNN) -- Former Massachusetts Gov. Mitt Romney on Wednesday sharply criticized an ABC News report on a classified U.S. program about covert action inside Iran, saying such reporting has the potential to jeopardize the United States, and its citizens.

"I was shocked, because a news organization with such a renowned reputation as ABC News would deem it appropriate to publish information about a covert action existing, and publish that not only to America, but to the entire world," the GOP presidential hopeful said while campaigning in Tulsa, Oklahoma Wednesday. "The reporting has the potential of jeopardizing our national security, stated quite plainly, it has the potential of affecting human life, we may never know."

Also citing the New York Times reporting last year about the NSA's electronic eavesdropping program, Romney added, "I think its time for leadership in the media to consider and adopt voluntary rules of responsible reporting with regards to matters of national security. Of course we have a First Amendment which we cherish and value. It provides for freedom of the press. But with this freedom goes the responsibility of the press."

Meanwhile, fellow GOP presidential candidate Tom Tancredo also criticized ABC News Wednesday for its reporting, saying in a statement, "Whether it is true or not, it is absolutely irresponsible for any media to publish a story like this that could jeopardize American lives," said Tancredo, a congressman from Colorado.