WASHINGTON — A pair of Senate Republicans on Monday unveiled what they call a conservative approach to protecting young undocumented immigrants brought to the US as children as Congress continues to race the calendar to the end of the DACA program.The bill from Sens. Thom Tillis, of North Carolina, and James Lankford, of Oklahoma, mimics legislation from Florida Republican Rep. Carlos Curbelo sponsored by 31 Republicans in the House, but includes efforts to appease conservatives and limit concerns they may have about eventually allowing the hundreds of thousands of eligible undocumented immigrants to become citizens.

Individuals brought to the US under age 16, who have lived here since 2012 and were under 31 at that time, who have achieved a high school diploma or equivalent and who are pursuing higher education, have held a job or have served in the military would be able to apply for permits for successive five-year periods, after which they could pursue legal permanent residency and eventually citizenship. Recipients would also need to pass extensive background checks and maintain a clean criminal record, according to text reviewed by CNN.

The bill adds a few measures not in previous bills. For one, to address conservative concerns about “chain migration,” a term that refers to immigration based on family relationships, the bill would prohibit individuals who achieve legal residency under the bill from sponsoring any family members. That restriction would not apply if they become citizens after the minimum 15-year process.

The bill also includes measures to crack down on illegal immigration beyond just addressing the undocumented youth previously covered under DACA. The bill tightens restrictions on overstaying a visa, currently the most common way immigrants to the US come illegally. It also would limit the Homeland Security department’s future ability to offer exceptions to categories of undocumented immigrants.

The issue has been pushed to the forefront since President Donald Trump announced he would end the Obama-era Deferred Action for Childhood Arrivals policy, with the two-year permits issued under the program beginning to expire in March. That delay has given Congress a deadline to make the executive branch policy permanent in law.

Lankford said in a news conference that Trump called him “late at night” after he put out a statement on DACA ending and they talked about the legislation.

“The President was fully engaged with that and was very supportive of the concept saying that’s the way to go,” Lankford said.

Still, he added, “I don’t believe, and we don’t believe, that this is a standalone bill,” saying more immigration fixes would be needed to pass the bill.

Sen. Orrin Hatch, R-Utah, also showed up at the news conference in support of the bill. He’s been a longtime supporter of this issue, including being an original advocate for a Dream Act over a decade ago.

Even with the Republican backing in both chambers, however, any proposal would need the buy-in of GOP leadership in the House and Senate and would need to survive negotiations with Democrats to pass — an uphill feat for any proposal. Tillis and Lankford demurred on questions about how their conversations with leadership about the bill have gone.

The bill, the Solution for Undocumented Children through Careers, Employment, Education and Defending our nation or SUCCEED Act, follows the pattern of previous proposals and sticks closely to the pathway in Curbelo’s bill.

There is widespread support in Congress for some type of DACA solution among both parties, but deep divisions remain about how to approach it.

Many Republicans have balked at eventually granting citizenship, something the right considers “amnesty.” Democrats, meanwhile, have supported bipartisan legislation called the Dream Act that would offer similar protections but would cover slightly more potential recipients and doesn’t include some of the other restriction measures in SUCCEED.

Republicans and Trump are insisting any measure be paired with some type of border security and possible immigration enforcement, and a fact sheet about the legislation makes clear that Lankford and Tillis both agree their bill must be part of such a package.

Any bill would need Democratic votes to path, likely in both chambers, to overcome Republicans that remain staunchly opposed to any solution for DACA-eligible individuals, and it’s unclear if the type of border security and enforcement Republicans will demand will cross a line for Democrats who say they will not trade the safety of DACA protectees’ friends and families for a fix.

On the House side, Speaker Paul Ryan has formed a working group of Republicans on all sides of the ideological spectrum to develop a proposal on the issue.