BEIRUT - Prime minister designate Saad al-Hariri warned on Tuesday it may take Lebanese parties more time to form a coalition government than expected, more than three months after the general election."Perhaps we need more time to arrive at a final formula," he said to reporters before a meeting of members of parliament from his party in Beirut.Lebanese politicians have repeatedly warned that the country - which has one of the world's highest rates of public debt - urgently needs to put a government in place, but they have jostled over cabinet positions."There is no doubt that some sides still stick to their terms, but, as we see, all of them retreat and concede a little," he said, adding that the new government needed to include all sides.The May 6 elections delivered a majority for the Shi'ite Hezbollah and its parliamentary allies, a reversal of the previous vote in 2009, when groups with Western and Saudi support won most seats.The result has further complicated Lebanon's tangled sectarian politics, as Sunni and Shi'ite Muslims, Christians and Druze compete among themselves for ministries.The delay in forming the government has prompted recriminations between rival parties.Last week, Hezbollah members of parliament warned that the delay risked Lebanon "sliding towards tensions.""We are a state that has problems, and we must form a national unity government in which cooperation between all the parties. Otherwise we will create a problem in the cabinet," Hariri said.The International Monetary Fund has warned that Lebanon needs "an immediate and substantial fiscal adjustment" to make its public debt - which measures about 150 percent of gross domestic product - sustainable.