Dr Rice said she discussed 'the importance of moving that initiative forward' with Arab ministers attending emergency Security Council meetings at UN headquarters on the Gaza crisis as well as the Israelis.

The initiative, outlined on Tuesday night by Egyptian President Hosni Mubarak, calls for limited cease-fire periods to allow the delivery of desperately needed humanitarian goods in Gaza and to give Egypt time to continue efforts to reach a permanent cease-fire.

Egypt also invited the warring Israeli and Palestinian sides for urgent meetings to resolve issues underlying the fighting, including securing Gaza's borders, reopening all crossings and lifting the Israeli siege.

'We are very much applauding the efforts of a number of states, particularly the effort that President Mubarak has undertaken on behalf of Egypt,' Dr Rice said. 'We're supporting that initiative.'

The initiative scored an initial success on Wednesday when Israel and Hamas, the Palestinian militant group that controls Gaza, agreed to a three-hour cease-fire to allow humanitarian aid to get to some of the 1.5 million Palestinians in the territory.

It was the first break in the 12-day air and ground offensive which Israel says it launched to end the Hamas rocketing of southern Israel.

'We have deep concerns about the humanitarian situation in Gaza,' Dr Rice said.

She said she received a report on humanitarian problems in Gaza from the U.S. Agency for International Development and had extended discussions on Tuesday with the Israelis about conditions in the territory.

'I'm pleased that the Israelis were able to open a humanitarian corridor, and to provide a pause for humanitarian action,' she said. 'But that needs to be repeated again and again becuase the people of Gaza need to be in a position to be able to get a lifeline to goods and supplies and to sanitation and to medical help, and so we're very focused on that.' Dr Rice said she spoke to Israeli Prime Minister Ehud Olmert and Foreign Minister Tzipi Livni on Wednesday 'about the need to make sure that that humanitarian corridor functions'.

She said she also planned to discuss the humanitarian situation with UN Secretary-General Ban Ki-moon.

On Wednesday, Dr Rice attended a series of meetings with Arab and European ministers trying to bring an end to the escalating conflict in Gaza.

'We're working very hard here for effective action,' she said.

'We believe a cease-fire is necessary, but it has to be a cease-fire that will not allow a return to the status quo' before Israel launched its offensive on Dec 27.

'We're also talking about how the council can best support the effective action that could be taken on the ground,' she said.

Dr Rice spoke to reporters outside the Security Council, where members were holding closed-door discussions on what action to take.

Arab nations have called for a vote on a legally binding resolution demanding a cease-fire, but the US, Britain and France want a weaker presidential statement. -- AP