Occupied Jerusalem: Israel believes a large international force may need to stay in south Lebanon for years until the Lebanese army is capable of dealing with Hezbollah itself, a senior Israeli official said on Thursday.

The head of the Foreign Ministry's Middle East bureau said the United States foresees first deploying a rapid reaction force once fighting between Israel and Hezbollah ends, then putting together a larger peacekeeping force.

Benny Dagan said the weakness of the Lebanese army relative to Hezbollah meant that the peacekeepers would have to be prepared for a long stay.

"It's going to take a long period of time until the Lebanese army would be able to function," Dagan said.

"It's hard for me to define if it's going to be one year or two years or three years. We're not talking here about months."

Dagan said an one important question would be Hezbollah's capabilities following the Israeli offensive.

The offensive has so far failed to stop Hezbollah rocket fire into Israel or drive its fighters deep into Lebanon.

World powers meeting on the conflict agreed on the need for an international military force with a UN mandate to secure southern Lebanon when fighting abates.

But there were no firm plans sealed at the crisis conference in Rome and there is still no sign of a ceasefire.

One diplomat said it would take days for the UN Security Council to come up with a resolution on a force capable of controlling the area.