BEIRUT, Aug 2 (Reuters) - Lebanese Prime Minister-designate Najib Mikati said on Monday he had hoped for a quicker pace towards the formation of a new government and that his efforts would not be open-ended. His comments after a meeting with President Michel Aoun underlined the challenge of forming a new government for Lebanon, where fractious politicians have been unable to agree even as the country falls deeper into economic crisis. "I had hoped for a pace that was faster than this in the government formation. It is a bit slow," said Mikati, who was designated prime minister last month after Saad al-Hariri abandoned his effort to form the new cabinet. The Lebanese pound, which has lost more than 90% of its value in less than two years, weakened. Dollars were changing hands at a rate of around 20,000 pounds after Mikati spoke, compared to 19,200/19,300 before his comments, a dealer said. Mikati, a wealthy businessman, said he would meet Aoun again on Thursday. Asked if he had a deadline for his efforts, he said: "As far as I am concerned, the timeframe is not open. Let he who wishes to understand, understand." The prime minister must be a Sunni Muslim in Lebanon"s sectarian power-sharing system. Abandoning his effort last month, Hariri said he could not agree with Aoun, the Maronite Christian head of state. The last government led by Prime Minister Hassan Diab resigned after the Beirut port explosion on Aug. 4 last year. It stays on in a caretaker capacity until a new one is formed.