"I don't want to raise any false hopes, but I hope that in the next 48 hours we will have some news on that - constructive, positive news," Kofi Annan said after holding talks with Hosni Mubarak, the Egyptian president, in Alexandria.
Israel has the embargo on Lebanon since its 34-day war with Hezbollah ended on August 14, saying it is aimed at preventing the Shia group from re-arming.
An Israeli foreign ministry spokesman said Israel would end the blockade once the Lebanese army, helped by international forces, could enforce an arms embargo on Hezbollah that he called "an essential element in the ceasefire".
"When they are ready to enforce the arms embargo, Israel will be ready to move," the spokesman, Mark Regev, said.
The Lebanese government has said it will protest at the UN against Israel's blockade, two days after Lebanese legislators began an open-ended sit-in at the parliament building to protest against the blockade.
Jihad Azour, the Lebanese finance minister, says Lebanon is losing about $40 million daily in customs and tax revenues, and commercial business.
Israel has allowed some commercial and aid flights into Beirut airport as well as some aid cargo ships.
Qatar Airways has resumed commercial flights to Beirut, landing its first plane since the conflict, with 118 passengers on board, on Monday.