PHILADELPHIA — Rudy Giuliani said Thursday he supports legislation barring firearms from people on a government terror watch list, and disagrees with the National Rifle Association's argument that this move would violate their Fifth Amendment rights to due process.

"I would support denying anyone on the terrorist watch list a firearm. Until they got themselves off the terrorist watch list, which you can do when you make an application explaining the mistake," he told the Washington Examiner at a press conference in Philadelphia hosted by the Republican National Committee.

"So if you're on the terrorist watch list, I would assume that we should treat you that way until you get yourself off it," he said. "I don't agree with the NRA on that position."

The watch list, which was was established in 2003 under the Bush administration, includes people suspected but not convicted of terrorism.

Earlier in the week he said he also supported tagging and monitoring people who appear on the government's terror watch list, and on Thursday, he expanded on those remarks.

"One of the two terrorists who beheaded the Catholic priest in France had been monitored," he told the Examiner. "And I was asked if I thought that was something we should consider in the United States."

"And I said I thought that was something, yes, we should consider in the United States," he added.

Pressed to explain whether the measure could threaten Americans' rights, Giuliani hedged.

"I still think it might be a good idea. I'd have to look into all the legal ramifications first. But I can't imagine why if someone's on the terrorist watch list you wouldn't want to keep an eye on them," he said.

"Maybe the list should be more accurate. Maybe we should make procedures for people to complain if they're erroneously on there easier. I would like the opportunity to take a look at what percentage is faulty. If the percentage is very high, like 20 percent, 30 percent, then I wouldn't do it until the percent was down to something like one or two percent," he added. "If the percentage were more like one or two percent, then I would do it. But I do think it's something to consider."

The watch list has been known to ensnare people with no known ties to terrorism, including an eight-year-old Cub Scout.

The terror database has also become the subject of a fierce debate in Washington, as a shooting at a gay nightclub in Orlando, Fla. renewed pro-gun control lawmakers' efforts to pass legislation blocking suspected terrorists from purchasing firearms.

Opponents of gun control measures, which included several GOP lawmakers and the NRA, argued the bill could violate the Fifth Amendment to the Constitution, which requires "due process of law," and says no one can be held to answer for a crime "unless on a presentment or indictment of a grand jury."

"We don't deprive a person of rights in this country simply because the executive branch put that person on a secret list," Rep. Justin Amash, R-Mich., said at the time in a statement to the Examiner.

"If the government believes that a suspect is plotting an attack, then it should charge that person and present evidence in court," he added. "The [proposed measure] instead denies rights to a person who hasn't been charged with or convicted of anything. It has far-reaching implications and undermines all our civil liberties, not just the Second Amendment."

Gabriel Malor, an attorney in Washington, D.C., told the Examiner, "Linking the watch list to the deprivation of a constitutional right is obviously, heinously and stupidly unconstitutional."

Ken White, an attorney who co-authors the libertarian popehat.com blog, concurred with Malor. "The huge due process concern is about limiting any constitutional right based on what amounts to an arbitrary, mostly un-reviewable, mostly secret, frequently clearly incompetent list of people."

"It's hard to imagine a bigger due process violation," he added. "The list is notoriously full of people who have done nothing at all."