FROM LEFT: Senate Majority Leader Mitch McConnell (R-Ky.), Karen Pence, Vice President Pence and House Speaker Paul D. Ryan (R-Wis.) acknowledge the crowd during a dinner at the 2018 House & Senate Republican Member Conference at the Greenbrier resort in White Sulphur Springs, W.Va. (Alex Wong/Getty Images)

President Trump on Thursday appealed to Republican lawmakers to embrace a controversial White House immigration plan as he tried to unify his party and blame Democrats for the impasse.

Trump's request, delivered in a luncheon speech at the yearly GOP policy retreat at the secluded Greenbrier resort, comes as his party remains beset with divisions on the issue — and as a deadline looms for the end of a program that protects hundreds of thousands of young immigrants from deportation.

If Democrats reject the framework, the president said, "we're just not going to approve it. So we'll either have something that's fair and equitable and good and secure, or we're going to have nothing at all."

He said that his offer potentially giving millions of undocumented immigrants a path to citizenship — anathema to many conservatives — in return for $25 billion in border wall funding and new curbs on legal immigration was meant to force Democrats into a political bind while showing that Republicans are serious about a solution after years of inaction.

And in an aside certain to needle Democrats, Trump again took aim at the term commonly used to describe immigrants who were brought to the United States as children and remain here illegally.

"Some people call it 'dreamers,' " he said, echoing a polarizing line in his State of the Union address Tuesday. "It's not dreamers. Don't fall into that trap."

But divisions between House and Senate Republicans on immigration were evident just hours before Trump issued his rallying cry, with a top senator talking up the prospect of passing a narrower immigration bill than the White House has proposed, while a House GOP leader embraced all the pillars of Trump's plan.

The push for an immigration bill has been put on the front burner by Trump's decision in the fall to cancel the Deferred Action for Childhood Arrivals program, or DACA, which is shielding 690,000 young immigrants from deportation. Trump asked Congress to act by March 5. Though a federal court ruling has left the deadline in limbo, lawmakers of both parties remain poised to act.

The issue is also tied up in a long-running standoff between Republicans and Democrats over federal spending levels, with Democrats threatening to block appropriations bills until immigration is addressed. The impasse sparked a brief federal shutdown last month.

Senate Republican Conference Chairman John Thune (S.D.) told reporters Thursday that a bill addressing DACA recipients and border security alone "may be the best we can hope for."

However, the White House framework goes much further. In exchange for offering a path to citizenship for 1.8 million young undocumented immigrants, the administration wants not only a $25 billion border wall "trust fund," but also new limitations on legal immigration — such as cuts to family immigration visas, which some Republicans call "chain migration," and the elimination of the program that distributes visas to citizens of certain countries by lottery.

House Republican Conference Chairwoman Cathy McMorris Rodgers (Wash.), appearing alongside Thune on Thursday, embraced the cornerstones of the Trump plan. Other GOP lawmakers, including Sens. James Lankford (Okla.) and David Perdue (Ga.), voiced clear opposition to the idea of pursuing a more narrowly tailored immigration bill.

"I'm not interested in a skinny version on immigration," Lankford said.

The discord highlights the challenge GOP leaders face in trying to forge a deal on immigration. In the House, conservatives have demanded a hard-line bill, with some arguing that the White House plan is too lenient on a path to citizenship. Rep. Mark Meadows (N.C.), the chairman of the hard-right House Freedom Caucus, said that conservatives remained opposed to any bill that provided dreamers with a "special pathway" to citizenship — including one based on the Trump framework.

Trump hinted at the need for compromise in his speech: "We have to be willing to give a little in order for our country to gain a whole lot."

But there was no deeper effort to sell Republican lawmakers on the proposal. There were retreat sessions scheduled on infrastructure, workforce development and the "national mood," but there was no separate session on immigration policy even as the split between conservatives and moderates, the House and the Senate, and various other factions have kept Republicans from cementing a deal.

Meadows said he was puzzled that the issue would not be put up for discussion during the retreat.

"The most pressing, must-do issue that we have is immigration," he said. "It's the thing that's dividing Republicans and Democrats. It's the thing that's dividing Democrats and Democrats, and it's the thing that's dividing Republicans and Republicans. And so we've got to find a consensus to move forward, and to ignore that at a planning retreat is certainly not a prudent move."

One lawmaker who attended the retreat — and spoke on the condition of anonymity to talk candidly — found it interesting that immigration was not listed as an official topic of discussion on the program. The lawmaker concluded that was because organizers wanted to find "areas that can promote the message of unity," and immigration did not fit that bill.

Senate Majority Leader Mitch McConnell (R-Ky.) said last month that he would open debate on an immigration bill if a bipartisan accord on addressing DACA was not reached by Feb. 8.

According to prepared remarks distributed by the White House, Trump was set to request that "the framework we submitted be the bill that the Senate votes on." During the speech, an ad-libbing Trump skipped that line, though he still delivered a robust case for pursuing the framework.

"The Republican position on immigration is the center, mainstream view of the American people, with some extra strength at the border and security at the border added in," he said.

GOP leaders will need Democratic votes to advance any immigration bill in the Senate, where there has been more appetite for a compromise bill. Still, Democrats and Republicans in the chamber remain far apart.

The top Senate Democratic negotiator, Richard J. Durbin (Ill.) has forcefully rejected the White House plan. He emerged from a meeting this week with top House and Senate lawmakers and Trump administration officials with no progress to report.

McConnell would not say which plan he favored as a foundation for the Senate debate but reiterated a commitment to handling the issue in an evenhanded way.

"We'll see who can get to 60 votes," McConnell told reporters, referring to the number needed to advance most legislation in the chamber.

A bipartisan group of senators has been meeting to gauge what kind of bill can attract broad support in the Senate. The flurry of meetings and working groups comes as lawmakers race to reach a deal on immigration sometime this month, with an eye on the expected March 5 deadline for DACA's cancellation.

Several GOP lawmakers said Trump put the onus on Democrats to come to the bargaining table by embracing what is effectively a broad amnesty for dreamers — and they suggested that Democrats will be to blame if the talks fall apart.

"There is a chilling effect when the president puts a path to citizenship on the table, and he's met with resistance among the people who should be the ones jumping up and down championing it," Rep. Lee Zeldin (R-N.Y.) said.

"The president is willing to go well past what the Democrats were asking for on DACA," said Perdue, an immigration hawk who said he would vote for legislation reflecting the framework. "What he wants is assurances that we won't be back here in three or four years doing the same thing again."

Erica Werner contributed to this report.