In the wake of the deadliest mass shooting in modern U.S. history, Sen. Tom Cotton (R-Ark.) responded on Thursday to calls for stricter gun control measures, saying that he would be “willing to entertain” the idea of regulating “bump stocks,” devices that the Las Vegas shooter used to speed up the gunfire of rifles he used in the massacre.

“I’d be willing to entertain any kind of device that turns a semi-automatic weapon, which is defined simply as one pull of the trigger equals one round discharge, into an automatic weapon, which means one pull of the trigger equals unlimited number of rounds discharged until your ammunition is expired or until your barrel overheats,” Cotton said in an interview with The Washington Post’s David Ignatius, “for the same reasons that we strictly control automatic weapons in this country.”

But Cotton, a former infantry officer in the U.S. Army, cautioned, “We shouldn’t expect to change the world with these things, but it’s something that we should consider once we have all the facts and circumstances at hand.”

The conversation about legislation to regulate bump stocks is picking up momentum in Washington, including among Republicans. On Thursday, House Speaker Paul Ryan (R-Wisc.), along with several other GOP members in the House and Senate, signaled the “need to look into” controls on the devices.

The National Rifle Association, the powerful gun lobby, also offered support for such a move.

“The NRA believes devices designed to allow semi-automatic rifles to function like fully-automatic rifles should be subject to additional regulations,” the group said in a statement on Thursday.

Cotton, who met with President Trump on Thursday, also repeated his calls for the president to scuttle the 2015 Iran nuclear agreement before an October 15 deadline. The Washington Post reported on Thursday that the president intends to announce next week that he will decertify the deal.

“It clearly is not in our vital national security interests. The president himself has said it’s an embarrassment and the worst deal in U.S. history,” Cotton said, arguing that the deal “puts Iran on a path to being a nuclear power.”

His position puts him at odds with U.S. Secretary of Defense Gen. James Mattis, who supports it.

“I respect General Mattis but I disagree with him here,” Cotton said, adding, “when dealing with a weaker but aggressive revisionist power, time is not on our side, time is on their side.”

Cotton also said it is “simply false” that the U.S. lacks a “credible military option” for dealing with Iran’s nuclear ambitions. On the contrary, he said, “we have a number of calibrated military strikes,” available citing military actions President Ronald Reagan took against Libya and strikes Bill Clinton launched against Iraq.

“We have options between capitulation under this deal and forcible regime change followed by a decade of occupation,” Cotton said, “and Iran needs to know that.”