LOUISVILLE — U.S. Sen. Rand Paul denounced the use of synthetic drugs but stuck to his position Wednesday that the push to ban the new-wave substances should come from state and local authorities, not the federal government.

The Kentucky Republican is using a procedural maneuver to try to block Senate bills seeking to ban the use of certain chemicals in synthetic drugs such as "bath salts" and other compounds that mimic marijuana, cocaine and methamphetamines.

He said that people who use synthetic drugs are foolish and that he's not opposed to laws against the substances.

"I do think that justice is better served by having the laws locally," Paul told reporters after speaking to a group of conservative lawyers.

One proposal to crack down on synthetic drugs has been approved by the House.

Paul did not say Wednesday whether he would try to stymie the House measure, but he sounded open to negotiations if supporters are willing to look at some minimum mandatory drug sentences that have been criticized by Paul.

"What we're doing is trying to work with them to say if they will discuss these mandatory minimums," Paul said. "Putting somebody in jail for 20 years for possession of marijuana is too much."

Kentucky Attorney General Jack Conway on Wednesday urged Paul to "stop holding up a vote on this bill." Conway, a Democrat who lost to Paul in Kentucky's 2010 Senate race, added: "The lives of Kentucky kids are at stake."