President Obama will ramp up his calls for comprehensive immigration reform during a trip to Mexico and Costa Rica that comes amid growing obstacles in Washington to his preferred pathway to citizenship for the 11 million illegal immigrants in the United States.

White House officials framed immigration reform as the "backdrop" of the three-day trek that begins Thursday, an attempt by Obama to move the needle on an issue in which he's left the bulk of negotiations to lawmakers. The president will look to build momentum for the reforms while not jeopardizing talks on Capitol Hill.

The trip takes on even greater importance considering the fragile state of negotiations. Sen. Marco Rubio, R-Fla., widely seen as the most influential conservative in the immigration debate, conceded that the current immigration bill crafted by a bipartisan group of senators would not pass the GOP-controlled House.

Obama, recently dealt a bitter defeat on gun control, is desperate to avoid another high-profile loss. Experts said the trip to Latin America is a crucial opportunity for the White House to allay fears that immigration reform would trigger a new flood of illegal immigrants into the U.S.

"Obama can present a more accurate picture of Mexico, which is extremely important in the domestic debate about immigration," said Democratic strategist Simon Rosenberg, who attended a meeting this week with Obama and Vice President Biden previewing the presidential trip. "There's a real concern about recreating the flow of [undocumented immigrants] from Mexico. Mexico has changed, and it's not something a lot of people in Washington know about."

Rosenberg said the president told the group he would sign the so-called Gang of Eight bill. But with conservatives already labeling that bill dead on arrival in the House, Obama and supporters of immigration reform could be forced back to the drawing board.

In a press conference Tuesday, Obama outlined his wish list for immigration reform but was hesitant to lay out any specific demands.

"Is it making the border safer? Is it dealing with employers in how they work with the government to make sure that people are not being taken advantage of, or taking advantage of the system?" he asked. "Are we improving our legal immigration system? And are we creating a pathway for citizenship for the 11 million or so who are undocumented in this country?"

The president will hold a bilateral meeting with newly elected Mexican President Enrique Pena Nieto on Thursday and speak to university students the next day, In addition to two press conferences during the Mexico-Costa Rica trip, Obama will do interviews with Spanish-language media.

"We'd expect these leaders to be broadly cooperative with our efforts to reform the immigration system," said White House spokesman Ben Rhodes, pointing to border security, economic interests and legal immigration as areas of discussion between the two allies.

If immigration talks fall apart -- as they have repeatedly in recent years -- both Obama and congressional Republicans would face blowback. The president has conceded that an inability to deliver comprehensive immigration reform was the biggest failure of his first term, and Republicans are looking to rebuild their image with Latino voters after a dismal showing among Hispanics in November's election.