Palestinian Authority President Mahmoud Abbas said Israel’s attack on the Gaza Strip is “genocide” and appealed for urgent action by the United Nations Security Council to stop the 11-day assault.

“The entire world opinion will accept no less than an urgent intervention by the Security Council to stop the fighting and deter the aggressor,” Abbas said at the UN in New York late today. “This is the message I am bearing.”

Abbas endorsed Egyptian President Hosni Mubarak’s proposal for an immediate cease-fire that would allow Israelis and Palestinians to discuss security arrangements to avoid another round of deadly violence. Mubarak said he asked Israeli and Palestinian leaders to accept his plan after meeting in Sharm el-Sheikh, Egypt, with French President Nicolas Sarkozy.

“Gaza today is living a new Palestinian catastrophe,” Abbas said. “I call upon this council to take the first necessary steps to save my people in Gaza, a resolution calling for an immediate cessation of Israeli aggression.”

Abbas addressed a Security Council meeting attended by UN Secretary-General Ban Ki-moon, Secretary of State Condoleezza Rice, British Foreign Secretary David Miliband, French Foreign Minister Bernard Kouchner and Arab League Secretary-General Amre Moussa.

The meeting followed a day of closed-door negotiations over a draft resolution that would call for a cease-fire in the Gaza Strip, withdrawal of Israeli military forces and deployment of an “international observes force” to implement the agreement.

Israel started a ground offensive on Jan. 3 in Gaza after a week of aerial bombardment aimed at stopping Hamas militants from firing rockets at Israeli communities. The Israeli government says it is carrying out a military operation to fight terrorism and is trying to avoid civilian casualties.

At least 580 Palestinians have died in the conflict, some 50 in overnight fighting, and 2,600 are wounded, said Mu’awia Hassanein, chief of emergency medical services in Gaza.