WASHINGTON (AP) — The House overwhelmingly passed bipartisan legislation that would solidify federal policies cracking down on the synthetic opioid fentanyl and its analogs in a bid by lawmakers to combat the nation’s opioid epidemic.

The HALT Fentanyl Act makes permanent a 2018 emergency rule that classifies knockoffs of fentanyl as Schedule I controlled substances, which results in harsher sentences for possession of the drug. The bill passed the House 321-104 and now heads to President Donald Trump for his signature.

The legislation, which applies to what are known as “fentanyl-related substances,” garnered support from nearly every Republican and many Democrats despite concerns that the bill does not address the root issues at hand and will add to problems in the criminal justice system.

Senate Majority Leader John Thune hailed passage of the bill and promised more legislative action to come.

“I don’t need to tell anybody about the horrible impact of drug overdoses in this country, many of them caused by fentanyl,” Thune said on the Senate floor. “In the coming weeks, we’ll be taking up legislation to address another aspect of the fight: securing our borders,” a nod to Republicans’ tax package, which includes billions of dollars in additional immigration enforcement and border security funding.

Proponents of the legislation argue that the bill will make it easier to stop drug traffickers by making the federal emergency rules permanent. Opponents say the framework does little to stem the epidemic and warn it will make it harder to conduct important research.

The bill does not include increased funding for law enforcement to conduct anti-drug trafficking efforts, nor funding for public-health efforts meant to reduce fentanyl addiction and deaths.

The bill’s supporters say that the reclassification will give anti-trafficking efforts clearer standards under which to operate as law enforcement combats the trade. Federal, state and local law enforcement have sought to break up the flow of fentanyl into the United States by targeting Mexican drug cartels and local gangs.

“A loophole that the cartels have tried to use to drive their illicit fentanyl into our country is by changing one part of the fentanyl chemical structure to create fentanyl analogs,” said GOP Virginia Rep. Morgan Griffith, one of the bill’s co-sponsors, during debate on the House floor.

“The cartels did this in an attempt to evade our criminal laws,” said Griffith, who argued that the bill would help prevent further fentanyl deaths and increase the potential for research into the drug and related substances.

Democratic New Jersey Rep. Frank Pallone said during debate that he opposed the bill because it uniformly criminalizes fentanyl-related substances.

Pallone said it will impede potential research into their benefits rather than provide an “offramp to substances found to have potential medical applications.” Pallone also chided Republicans for saying they aimed to tackle the opioid epidemic while supporting the Trump administration’s cuts to federal agencies tasked with research and public-health policy.