At issue is a June settlement between the U.S. government and Texas-based Defense Distributed company that will allow it to legally publish gun blueprints online.
NRA spokesman Dana Loesch has said trying to outlaw the guns, or the technology that produces them, would be "absolutely unenforceable".
North Carolina Attorney General Josh Stein on Wednesday joined the multi-state lawsuit to block the release of the blueprints, saying they would allow underage individuals and people with a criminal history or mental health issues access to weapons. The plans were downloaded about 100,000 times until the US State Department blocked it, claiming the distribution beyond the US borders violated laws on weapons export. During a news conference at the Capitol, the lawmakers described it as a "deadly mistake" and a "self-inflicted public safety crisis".
Previously, Attorneys General in eight Democrat-ruled U.S. states sued the Donald Trump administration over a June settlement with Defense Distributed.
The plans were cleared for publishing beginning August 1.
Connecticut Sen. Richard Blumenthal was more graphic, saying that if Trump does not block sale of the 3D guns, "Blood is going to be on his hands".
3D printing is expensive and time-consuming, said Dukes and it costs more than buying a legal gun.
The gun plans were pulled from the internet in 2013 by order of the State Department under worldwide gun trafficking laws.
A United States federal judge in Seattle has blocked the release of software that allows consumers to 3D-print firearms.
Since the weapons "did not create a military advantage", he told the judge, "how could the government justify regulating the data?"
But it is unclear how effective the temporary restraining order is since the schematics for one of its guns - The Liberator - were posted on the company's website on Friday - five days ahead of the company's announced release date.
Five years ago, Wilson built the world's first fully fireable plastic handgun.
"All you need is a little money and you can download a blueprint from the Internet to make a gun at home, " said Senate minority leader Chuck Schumer. They (Democratic attorneys general) figure if they blame Trump for everything, they can get a win.
Other Republicans have also expressed concern, with Alaska Senator Lisa Murkowski tweeting: "Even as a strong supporter of the Second Amendment - this is not right". Federal law passed in 1988, crafted with the NRA's support, makes it unlawful to manufacture, import, sell, ship, deliver, possess, transfer, or receive an undetectable firearm.
The eight states and the District of Columbia argue that permitting people to make their own guns violates state controls over weapons.