Immigration reform will not be part of this year’s omnibus spending bill, Senate Republicans said Thursday after a meeting at the White House.

Republican and Democratic lawmakers involved in immigration negotiations are trying to find a way to pair citizenship for those in the Deferred Action for Childhood Arrivals program, or DACA, with enhanced border security measures.

While there is interest in addressing DACA from both sides of the aisle, some worry including it could pull the whole effort into a cascade of debate over the broader immigration system.

“What we are trying not to do is fall down the slippery slope of comprehensive reform,” Republican Sen. Thom Tillis of North Carolina said.

Watch: Rep. Ruben Kihuen on His Journey From Undocumented Immigrant to Congressman

Lawmakers of both parties are taking steps to prevent pending legislation in the Senate to address undocumented people who came to the country as children from snowballing into a larger immigration overhaul.

While the main focus of the GOP is overhauling the nation’s tax code, discussions on an immigration bill are picking up. Seven Republican senators met with President Donald Trump on Thursday to discuss the legislation. Earlier this week, Sen. Tom Cotton of Arizona also met with top White House advisor Stephen Miller, who has taken a leadership role on the immigration issue. An aide declined to comment on the nature of the meeting.

Some Republicans are also seeking to address chain migration — immigrants that follow or accompany lawful residents — in the pending legislation. It’s a key demand of the White House and one that Cotton and Sen. David Perdue of Georgia are advocating as part of their legislation — referred to as the RAISE Act — that would implement a merit-based immigration system.

Senate Minority Whip Richard J. Durbin, who along with Republican Sen. Lindsey Graham of South Carolina is leading the charge on negotiations for their so-called DREAM Act, said conversations remain ongoing.

“Don’t expect to put all immigration reform on the shoulders of these DREAMers,” the Illinois Democrat said. “We’re trying to focus on the appropriate type of border security to complement the DREAM Act, and that really is the exclusive focus at this point.”

Durbin said Republicans have yet to lay out exactly what type of border security measures they want in the legislation. While the whole bill from Cotton and Perdue is unlikely to be incorporated, Durbin said he is open to addressing the issue of chain migration.

“Sen. Cotton goes far beyond what I think we can achieve in the DREAM Act, but we will, of course, be addressing some aspects of family unification. I think that needs to be part of it,” he said.

After the White House meeting, Graham outlined what he thought an agreement to pass his legislation might look like.

“I think you can get strong border security with a wall component. I think you can deal with the problem of kids being dropped off from Central America, left on our doorstep. I think you can do away with the diversity visa lottery system since we did away with it before,” Graham said, referring to a visa program Trump spotlighted this week in a series of tweets after a deadly attack in New York City.

“I think you can get interior enforcement including ‘Kate’s Law’ for the DREAM Act,” Graham added. “Kate’s Law” is the colloquial name for legislation that would increase penalties for people who return to the U.S. illegally after being deported.

Still, Senate Majority Whip John Cornyn said 2018 was a more likely timeline.

“This, I think more likely than not, will be part of a January, February time frame. But if we can cut a deal earlier than that, that’s fine with me too. But it won’t be part of the omnibus. That’s the pipe dream of some of the Democrats who think this is going to get swept up in a big year-end spending bill,” he said.

Congressional Hispanic Caucus Chairwoman Michelle Lujan Grisham issued a statement after the White House meeting let out and the result surfaced.

“At stake are the lives of 800,000 young American patriots who are at the mercy of Republican back room deals,” the New Mexico Democrat said. “It is reprehensible that the President and Senate Republicans would devise a scheme to hold the Dream Act hostage.”

Jennifer Shutt contributed to this report.