WASHINGTON — Haiti President Michel Martelly, who has been pilloried at home, received rave reviews in his first major visit to Washington this week after signaling a willingness to compromise on long-delayed elections.

Some hope he was not “blowing smoke.”

Haitians back on the island say the real test of whether their often-combative president has indeed changed politically will come over the next few days. On Tuesday, opposition leaders are to begin phase two of negotiations with Martelly to hammer out the changes necessary to make the balloting possible.

“The support of the U.S. is so fundamental for the president,” said Sauveur Pierre Etienne, leader of the opposition Organization of People in Struggle (OPL), one of 53 political parties that ended 10 days of negotiations Wednesday with the government over elections and governance. Both sides agreed on holding one election this year.

“Did he go and say one thing, and when he returns, he will do something else?” Etienne said. “Washington will quickly expose him . . . because we’re in a process of dialogue where today we’ve found a compromise.”

In December, Martelly took an important step in allowing elections by agreeing to publish a new electoral law, backing down from a plan to dismiss some senators early. The law’s publication averted a deeper political crisis, and quieted the street protests calling for his resignation.

President Barack Obama said he was pleased with Martelly’s efforts on elections, which would “help resolve some of the political roadblocks that stalled some progress.”

The scheduling of the long-overdue elections was a top agenda item during Martelly’s visit. U.S. lawmakers and others had criticized his appointment of 140 mayors without voting. Municipal elections have been delayed for almost three years and senatorial balloting by almost two.

The long-awaited Oval Office meeting was the first between Obama and Martelly, who has faced increased domestic and international pressure to schedule the delayed elections.

Obama noted progress since the country’s Jan. 12, 2010, earthquake. He cited improvements in Haiti’s economy, security and schools, but said it has been “a very slow and difficult process.”

While the United States provides Haiti with about $400 million in aid annually, some have questioned the Obama administration’s commitment. South Florida immigration activists, 100 members of Congress and newspaper editorial boards have called on Obama to approve a Haitian Family Reunification Parole Program. The Department of Homeland Security has approved family-based visa petitions for 110,000 Haitians, who have yet to be reunited with family members in the United States.

Also, the Global Haitian Diaspora Foundation called on the Obama administration to, among other things, deploy the remaining funds for earthquake recovery; support Haiti’s efforts to obtain loans from the World Bank and other institutions; and help organize an international donors’ conference to effectively deploy the funds world leaders pledged after the disaster.

Obama did not address the criticisms, but said the United States remains committed to helping the country.

“I think we are all recognizing that we have a lot more work to do,” Obama said. “We want to make sure that all the children of Haiti are able to lead lives of opportunity, prosperity and security.”

Martelly thanked the U.S. “for always standing by the Haitian people,” and said he looked forward to discussing security, his country’s fight against narcotics trafficking and his “engagement in building a strong democratic state.”

Still, Haiti faces challenges, criticism that Martelly did not back away from during a meeting Wednesday with U.S. lawmakers. Like the White House, members of Congress voiced concerns about human rights abuses, judiciary reform and corruption.

Martelly “took careful notes on everything we discussed and addressed every question,” said U.S. Rep. Ileana Ros-Lehtinen, R-Miami, noting that Martelly told lawmakers his government is beefing up security and tackling corruption.

Ros-Lehtinen is a member of the House Foreign Affairs Committee and organized a breakfast with Martelly, who also met with Secretary of State John Kerry and members of the Congressional Black Caucus.

Ros-Lehtinen said there is a “great deal” of support for Haiti in Congress, but there are concerns that the aid be spent wisely.

“Maybe he is blowing smoke, but he is taking our questions and our concerns seriously,” she said. “He’s addressing them. For every point that we had, he said, ‘We’re aware of it, we have this program, this plan.’ ”

But she said lawmakers want “proof with action,” and that she plans to lead a South Florida delegation to Haiti next month.

Martelly has been criticized in Haiti for a reluctance to compromise, forcing the United States and others in the international community to spend much of past year trying to avert a deeper crisis in the country. Whether the election actually takes place will depend on Martelly’s willingness to compromise further. As he met with Obama, about 40 people protested outside the White House against the visit with coffins and signs.

Pierre Esperance, a leading human-rights advocate in Haiti, said the slew of anti-government protests, demands for Martelly’s resignation and discontent among the international community had isolated Martelly and might have influenced his new posture.

He’s no longer “beating his chest” and refusing to back down, Esperance said.

“The president has become wiser. He is less arrogant now,” Esperance said. “But is there change? We have yet to see big change. We’ve seen little timid steps.”

Yet, Martelly’s appearance in Washington suggests that “the U.S. is fully on board,” said Robert Fatton, a Haiti expert at the University of Virginia. Kerry told Martelly he had “great respect for the road” he’s put Haiti on.

“Secretary Kerry’s comments and the official visit with President Obama signal a new honeymoon with President Martelly,” Fatton said. “The question is whether it will be long-lasting.”

In the past two weeks, different parts of Haiti have been plagued by protests, some of them violent. Several opposition groups announced a protest for Friday — the day 28 years ago that Haiti began its difficult transition to democracy with the departure of dictator Jean-Claude “Baby Doc” Duvalier into exile. At the same time, Martelly wraps up his four-day Washington visit with a stop at the Organization of American States.

Later this month, Martelly will visit France and then travel to Rome, where the first Haitian Cardinal, Chibly Langlois, chief mediator during the political negotiations, will receive his gold ring and red beret from Pope Francis.

Etienne said Martelly has perhaps become more “conscious of what’s at stake” — his legacy and the country’s stability — three years after he was elected to a five-year term.

“If the president is bluffing, then the Congress or the Obama administration won’t even need two weeks to call his bluff,” Etienne said.