National Rifle Association president David Keene called Colorado’s backlogged system for gun background checks an unreasonable burden on a citizen’s right to bear arms and addressed the matter with Gov. John Hickenlooper when the two met privately Thursday.

“If I were a Colorado resident, and told I had to wait an undetermined period of time to buy a gun, I would go to court,” Keene told The Denver Post on Thursday before the meeting.

The checks, which federal law says should take no longer than three business days, have taken as long as nine days to begin processing since the mid-December shooting of 20 children and six adults at a Newtown, Conn., elementary school. The wait continues to average about seven days in the queue.

The Colorado Bureau of Investigation — facing questions over its inability to meet the three-day federal gun background-check mandate — told The Post on Tuesday it would have the state’s attorney general review its policy for processing the checks.

Keene said he would tell Hickenlooper that the issue would have to be rectified, but he would not specify what actions, if any, the NRA would take if the issue persisted.

After the meeting, Keene said background-check wait times were discussed, but he did not elaborate on any specifics.

“We had a good meeting,” he said. “I told him (Hickenlooper), ‘We’re open, and we’ll agree and disagree on different things, but we are available to talk and provide facts and work with you in any way we can.’ ”

Keene, 67, was elected NRA president in 2011 and has been a board member since 2000.

Keene told The Post that the NRA has always considered Hickenlooper to be “a pretty reasonable and thoughtful guy” but that the governor is also a Democrat who is being pushed by his party’s national leadership to do something about guns and gun violence.

After the meeting, Hickenlooper released a statement saying he appreciated Keene’s willingness to come and discuss the issues.

“While we might not agree on a number of things, there will certainly be places we can find common ground,” Hickenlooper said in the statement.

On Tuesday, Colorado Democrats announced an extensive package of gun bills, which included a measure to hold manufacturers and sellers of assault-style weapons legally liable for damage inflicted with such firearms.

Keene blasted that plan Thursday morning.

“From a policy standpoint, it’s foolish,” Keene said. “You can’t sue them (manufacturers and sellers) because someone bought a legal product and then did something wrong with it.”

Congress in 2005 passed a law preventing gunmakers from being liable in civil cases when criminals use their products.

Keene also planned to discuss with Hickenlooper the role of mental illness in last year’s mass shootings, he said.

While he was unaware of the number of mental-illness records in the FBI’s National Instant Criminal Background Check System — 2.5 million, or 27.7 percent of all active rec-ords in the NICS Index — he said the system needed to be better but offered no details into to how improve it.

“I’m not an expert, and none of us at NRA are experts on mental health. … But it is very complicated because it is in fact true that most people who have mental problems are no more a threat than people who don’t have mental problems,” he said.

Yet there are people who are not “in the gray area,” and should not have access to guns, he said.

Keene singled out suspected Aurora movie-theater gunman James Holmes, who allegedly made threats of violence to his therapist but had no mental-illness record that would have flagged him from buying a gun.

“We can all agree that if we can identify the right people and prohibit them, that’s what we ought to do, but the question is, How do you do that?” he said.

The bottom line, Keene said, is that emotions on both sides of the debate are so inflamed that finding any middle ground to have an open conversation concerning all gun-control practices will not be easy.

“I think there are a lot of things we can do and there are a lot of common ground on those things,” Keene said. “But when it comes down to blaming a firearm for the act of a criminal, no, we have no desire to compromise on something like that.”

Ryan Parker: 303-954-2409, rparker@denverpost.com or twitter.com/ryanparkerdp