Haiti Prime Minister Garry Conille has resigned from office, giving in to political pressure from President Michel Martelly to step down.

Conille sent a letter to Martelly shortly after 10 a.m. Friday, almost an hour before he was supposed to meet with the president and ministers at the National Palace, several sources confirmed.

The National Palace issued a press release just before 2 p.m. confirming the resignation, saying Martelly will address the nation at 7 p.m. Friday.

“We are muddling through from crisis to crisis,” said Robert Fatton, a Haiti expert at the University of Virginia. “The immediate future is likely to be very turbulent and a major crisis may be in the making.”

For days, Conille, a former UN diplomat and gynecologist, had been under pressure to step down, with presidential advisers delivering the request in person. On Thursday, rumors circulated that Martelly would formally ask for Conille’s resignation in a letter.

The international community, influential business leaders and top Haitian politicians had been scrambling for days to prevent a political confrontation that could lead to the ouster of Conille just four months after he took office. But all their efforts failed.

The presidents of both the lower chamber of Parliament and the Senate told diplomats and Conille that they were opposed to the ouster, and feared that it would deepen the crisis in Haiti. But others say that with the president and prime minister unable to see eye-to-eye, Haiti was facing a crisis of governance.

Conille and Martelly have been at loggerheads over issues of the nationality of government officials — including that Martelly has an American passport — an investigation of $300 million in post-earthquake contracts and who controls government ministers.

On Thursday, as speculation spread about whether the prime minister would stay or go, the head of the U.N. peacekeeping mission in Haiti read a statement on what the mission called “a series of repeated crises between the executive and legislative powers that undermine the proper functioning of the institutions and the democratic process,” over the past few weeks.

“The political deadlock and institutional paralysis between the government, Parliament and the president does not reflect the commitments they have undertaken vis-à-vis the Haitian people and are not likely to create the necessary conditions for recovery of the economy and the consolidation of democracy,” Mariano Fernandez, special representative of the U.N. Secretary-General and head of the mission in Haiti, said in a statement.

As Fernandez spoke, government ministers and their chiefs of staff were complying with a Senate commission investigating the nationality of government ministers.

In his statement, Fernandez said “2012 could prove a turning point for Haiti in terms of reconstruction, economic growth, investment and strengthening of political institutions and governance.”

Though negotiations have been taking place for days over Conille’s replacement, observers say there is no telling when Haiti will get a working government. It took five months for Conille to be appointed as prime minister, and he was Martelly’s third choice. Already names are being circulated, all three of them close to the president.

There is no guarantee that any of those choices will be approved by the Parliament, which has been at odds with the president since his May 14, 2010, inauguration.

“President Martelly, like all previous Haitian presidents, is not willing to have a prime minister who has his or her own agenda and who seems to be protected and defended by the international community,” Fatton said. “Haitian politics has not changed significantly in this respect; Martelly is maintaining the tradition that only one figure, the President, can be the ultimate and indeed sole ‘decider.’ Sharing power is simply not yet in the DNA of Haitian governance in spite of the constitution.”