Saad Hariri announced Thursday that he was stepping down as Lebanon's prime minister-designate after the Hezbollah-led opposition rejected a team he proposed earlier this week. “Given that my commitment to forming a government of national unity has run up against difficulties that everyone now knows about, I announce that I have informed the president of the republic that I have abandoned trying to form a government,” he told journalists in Beirut. “I worked for 73 days to achieve this objective but each time the rounds of negotiations were hampered one way or another,” added Hariri, saying the team he had proposed would have been a “real opportunity” but was “frittered away through conditions imposed” by the minority. UN Secretary General Ban Ki-moon expressed regret that three months after elections Lebanon's political parties were still unable to find agreement on a unity government. “The Secretary-General regrets that at the moment it has proven impossible to form a new government in Lebanon,” UN spokeswoman Marie Okabe said. But the United States voiced hope that a new government could be decided soon in Lebanon but said it had “no immediate” concern about the delay in forming one. “We hope that both sides will resolve the impasse quickly and respect the process that's outlined in the Lebanese constitution, put together a government,” the State Department's Philip J. Crowley told reporters. Hariri and his allies won a healthy majority of 71 seats in the 128-member parliament in the June election, while the Hezbollah camp got 57. “I hope that this decision will be in the interests of Lebanon and will permit a relaunch of dialogue,” he added. The announcement comes after more than two months of fruitless efforts to form a government. The rejection of Hariri's proposed team sparked fears of new political crisis in a country where bickering led to deadly fighting only last year. On Monday, Hariri proposed a 30-seat coalition cabinet to President Michel Sleiman but Hezbollah chief Hassan Nasrallah quickly accused him of proposing a line-up that would only complicate the situation. “I do not believe this way of doing things will lift Lebanon from the crisis over the formation of the new government,” Nasrallah said. “It will make the problem more complicated.” Hezbollah accused Hariri of trying to impose a “de facto government” contrary to the spirit of a national unity cabinet. Hariri, the son of assassinated ex-premier Rafiq Hariri and head of the parliamentary majority, was named premier on June 27. Tough negotiations led to a deal on the number of ministers each political camp would have in the cabinet, with 15 going to Hariri's alliance, 10 to its opponents and the president appointing the remaining five. However, the various factions have been unable to agree on just who gets what ministries.