Cory Booker said he backs legislation that would get Americans “thrown in jail” for owning “assault weapons” if they do not hand them over in a buyback program in which they would be sold to the government.

Booker, a senator for New Jersey and 2020 presidential hopeful, said that incarceration would be an option after a “reasonable period” following the buyback offer.

“Again, we should have a law that bans these weapons, and we should have a reasonable period in which people can turn in these weapons. Right now we have a nation that allows in streets and communities like mine these weapons that should not exist,” Booker said on CNN on Monday.

Booker’s statement was in response to a question asked by CNN’s Poppy Harlow about his gun control proposals. “Senator Booker, before you go, one final question on your gun proposal since you just released it this morning: Your competitor in the 2020 race, Congressman Eric Swalwell has also, like you, proposed an assault weapons ban,” Harlow said.

“He’s proposing a buyback program where Americans who currently have those guns could sell them essentially to the government, but if they don’t, within a certain period of time, they would be prosecuted … thrown in jail, perhaps. Are you supportive of the same?”

[ Opinion: Cory Booker wants to regulate guns like cars — except when he doesn’t]

Booker, 50, responded affirmatively that the law would be enforced with criminal sanctions after a “reasonable period.” He had said earlier: “The critical thing is, I think most Americans agree, that these weapons of war should not be on our streets.”

Earlier in the day, Booker unveiled a 14-part gun control plan, which included a ban on assault weapons including high capacity magazines.

“The biggest thing in the proposal is a national gun licensing program, which would force Americans to apply for 5-year gun licenses before obtaining a firearm. The process would include fingerprinting, an interview, gun safety courses, and a federal background check,” Booker said in a statement announcing the proposal.