Republicans stressed a “security first” approach to immigration reform Sunday but said the prospects for a deal this year are far from certain, in part because of distrust of the Obama administration.

When asked by George Stephanopoulos, host of ABC’s “This Week,” whether a reform package could make it to the president’s desk before 2015, House Budget Committee Chairman Paul Ryan (R-Wis.) said: “I really don’t know the answer to that question. That is clearly in doubt.”

Ryan, House Majority Leader Eric Cantor (R-Va.) and Louisiana Gov. Bobby Jindal (R) said in separate appearances on Sunday news shows that they would support an immigration overhaul package, but only if it focused first on security. The comments echoed a set of broad principles announced late last week at a GOP retreat.

“We don’t think that we can allow this border to continue to be overrun, and if we can get security first, no amnesty, before anything happens, we think that is a good approach,” Ryan said. “This is not a trust-but-verify; this is a verify-but-trust approach.”

Trust will be crucial to any bill making its way through Congress, Cantor said. Republicans, he said, are concerned by President Obama’s comments in his State of the Union address last week that he will “not stand still” as Congress remains gridlocked and will use his executive powers to change and enact policies.

“That sort of breeds this kind of distrust, and I think we’re going to have to do something about that in order to see a way forward on immigration,” Cantor said on CBS’s “Face the Nation.”

Other Republicans, including Ryan, have made similar statements.

Obama told CNN’s Jake Tapper last week that he considered it a sign of progress that House Republicans are preparing guidelines for reform. “There is a desire to get it done, and that, particularly in this Congress, is a huge piece of business,” he said.

White House Chief of Staff Denis McDonough said Sunday that a package should include a pathway to citizenship for the nation’s 11 million undocumented immigrants. “We don’t want to have a permanent separation of classes or two permanent different classes of Americans in this country. We’re just not going to live with that. This is an important first step,” McDonough said on “Face the Nation.”.

But those comments came after Obama, in his interview with Tapper last week, suggested he could be open to a bill lacking a pathway to citizenship.

“If the speaker proposes something that says, right away, folks aren’t being deported, families aren’t being separated, we’re able to attract top young students to provide the skills or start businesses here and then there’s a regular process of citizenship, I’m not sure how wide the divide ends up being,” Obama said.