BEIRUT — Lebanon formed a government Tuesday that is controlled exclusively for the first time by Hezbollah and its allies, affirming the Iranian-backed movement's increasingly powerful role in the country and raising concerns about Lebanon's ability to halt a spiral of economic and political collapse.

Protesters, who have been demanding a government aligned with none of the existing political factions, called for fresh demonstrations against the new cabinet, which they said failed to meet their demands for substantial change.

The dominant role in the government’s formation played by Iranian-allied Hezbollah, which proposed the candidacy of Prime Minister Hassan Diab in December and has pushed forcefully in recent days for his lineup of ministers, risks alienating some of Lebanon’s traditional Western allies, including the United States, at a time when Lebanon’s collapsing economy urgently needs international assistance.

The announcement of a cabinet by Diab, a professor at the American University of Beirut, broke three months of political deadlock during which Lebanon had no functioning government and the country continued a slide toward economic and financial collapse. The previous prime minister, the Western-allied Saad Hariri, resigned in October in response to massive street protests demanding a complete overhaul of the country’s decades-old system of corrupt, sectarian rule.

Supporters of the new government are hoping that Diab, a relative unknown, can win over the protesters and convince foreign donors that he represents a new breed of politician capable of implementing reforms. The chief demand of the protest movement was for a cabinet of technocrats, devoid of political affiliation, who would break the vicious cycle of patronage and corruption that has pushed Lebanon into crisis.

Diab promised in a televised address that he would meet the protesters’ demands and carry out reforms.

“This is a government that represents the aspirations of the demonstrators who have been mobilized nationwide for more than three months,” he said.

But as the names of the new ministers leaked to the press in the days leading up to the announcement, it became clear that most, if not all, are proteges of the existing elites. Last-minute haggling among politicians over the final composition of the cabinet was played out in the media, giving another indication that this government offers neither a break from the past nor a reason to believe it can unite the dangerously fractured country, analysts said.

It is also a government representing only one of the two major blocs in the country’s parliament, meaning that Lebanon now has what people are calling a “one color” government for the first time since Syrian troops withdrew from the country 15 years ago.

Though Hezbollah has steadily increased its role in mainstream politics over the past 15 years and has held seats in many previous governments, this is the first time a government has been formed that does not include Western allies, calling into question its ability to win the support needed to secure international aid.

Even if the government turns out not to be Hezbollah-controlled, it will be seen as “a Hezbollah-directed government because of the way the prime minister was chosen,” said Maha Yahya, director of the Carnegie Middle East Center in Beirut. “It’s going to be very hard to walk that one down.”

“It is a government that will have to walk a fine line between providing a protective cover for Hezbollah and being acceptable to the international community,” she added.

Hezbollah will control just two ministries in the 20-member cabinet, according to analyses of the ministers’ allegiances in the Lebanese press, by diplomats and by people close to Hezbollah. The lion’s share of seats goes to supporters of the group’s Christian ally, the Free Patriotic Movement headed by Gebran Bassil, the outgoing foreign minister and son-in-law of Lebanese President Michel Aoun. Others are distributed among other Hezbollah allies, including the Shiite Amal movement and other smaller parties belonging to the country’s Christian and Druze religious groups.

The government’s composition also signaled a return to influence in Lebanon for the Syrian government of President Bashar al-Assad for the first time since Syrian troops were forced to withdraw from Lebanon under pressure from mass protests in April 2005. Several of the parties represented are known for their loyalties to Assad during the 9-year-old Syrian war, and Hezbollah fighters played a key role in ensuring Assad’s survival in the face of a nationwide rebellion.

Also on Tuesday, the Lebanese authorities freed an American freelance journalist who had been detained two days earlier on suspicion of sending footage of anti-government protests to an Israeli news outlet.

Nicholas Frakes, 24, said he is happy to be free and looking forward to “getting back to reporting the news.”

The Lebanese authorities had accused Frakes of live-streaming footage of violent protests to the Israeli news outlet Haaretz, in violation of Lebanese laws forbidding interaction with Israel, an enemy state. Haaretz issued a statement saying it had no contact with Frakes and had been using footage supplied by the international news agency Reuters.

Haidamous reported from Washington.