By Laura Trevelyan
BBC News, United Nations
The UN Security Council has abandoned its attempt to agree a statement on the humanitarian situation in the Gaza Strip following a blockade by Israel.
Hundreds of thousands have surged into Egypt to buy supplies
Israel tightened its embargo after a sharp rise in rocket attacks from the Palestinian territory on its southern towns, leading to acute shortages.
The UN statement, which must be agreed by all 15 members of the council, would have called for an end to hostilities.
But Libya wanted language more critical of Israel than the US would accept.
Bridging the divide
What began as an effort to make a statement on the humanitarian situation in Gaza following Israel's closure of the border crossings failed because the fault lines on the Middle East run so deep in the Security Council.
After eight days of negotiations, there was no bridging the divide between the US, a staunch ally of Israel, and Libya, representing the Arab world.
Unlike Security Council resolutions, which are voted on, statements have to be agreed by all 15 countries.
On Friday night, it looked as though 14 nations were supporting a statement calling for an end to Israel's blockade and an end to rocket strikes against Israelis launched from Gaza.
But then Libya, on behalf of Arab countries, wanted to change the language on Monday to be more critical of Israel's role.
At that point diplomats decided to abandon their efforts. Libya's ambassador blamed the US for rejecting the changes sought by Arab countries.
But the US deputy ambassador at the UN, Alex Woolf, said: "It's no mystery that we haven't been able to crack the nut of Middle East peace for quite some time and that's because there are fundamental disagreements.
"We work at, we gave it a good faith effort. I think everybody tried hard to see if we could accomplish this," he said.
The Middle East is a fraught subject at the United Nations. Arab countries point to the fact that America, a permanent member of the Security Council with the power to veto decisions, protects Israel from criticism.
In the UN general assembly, where the developing world has a majority, there is frequent criticism of Israel.