UNITED NATIONS (AP) -- The United States vetoed a UN Security Council draft resolution Saturday that sought to condemn an Israeli military offensive in the Gaza Strip and demand Israeli troops pull out of the territory. U.S. Ambassador John Bolton said the Arab-backed draft resolution was "biased against Israel and politically motivated."

"This resolution does not display an evenhanded characterization of the recent events in Gaza, nor does it advance the cause of Israeli-Palestinian peace to which we aspire and for which we are working assiduously," he told the Security Council.

The veto unleashed a flurry of criticism in the Middle East. "This decision by the U.S. government gives unlimited cover to commit more massacres of innocent Palestinians," said Ghazi Hamad, spokesman for the Hamas-led Palestinian government. "This is a shame on the American administration, which says it is trying to promote human rights and democracy in the Middle East." U.S. Secretary of State Condoleezza Rice said, however, the draft resolution would have aggravated the situation in Gaza because it contained "inflammatory and unnecessary language."

"We do not believe the resolution was designed to contribute to the cause of peace," she said in a statement.

In Beit-ul-Moqaddas, Israeli Foreign Ministry spokesman Mark Regev agreed the draft was one-sided. "It's good that it wasn't accepted by the Security Council," he said.

The draft received 10 votes in favor and four abstentions, along with the U.S. vote against. Britain, Denmark, Japan and Slovakia all abstained. The U.S. is one of five permanent members of the council that have the power to veto resolutions.

It was the second U.S. veto this year of a Security Council draft resolution concerning Israeli military operations in Gaza. The U.S. blocked action on a document this summer after Israel launched its offensive in response to the capture of an Israeli soldier by Hamas-linked Palestinian militants.

Palestinians strengthened calls for Security Council action after an early morning Israeli artillery barrage in the northern Gaza town of Beit Hanoun killed 19 people recently.

In an open session of the General Assembly on Thursday, Palestinian UN observer Riyad Mansour called the attack "state terrorism" and said the perpetrators should be held accountable under international law for war crimes.

Israel has expressed regret for the loss of life in Beit Hanoun but said it will continue operations to stop militants from launching rockets into Israel.

Qatar's UN Ambassador Nassir Al-Nasser warned in the Security Council meeting that the failure of the body to act on the draft would lead to more Israeli violence against Palestinians.

"Any lukewarm reaction or response on our part gives the impression we are shirking from our humanitarian responsibilities," said Al-Nasser, who sponsored the resolution on behalf of the Palestinians. Qatar is the only Arab nation on the council. Arab League Secretary-General Amr Moussa said the veto "will only increase the anger" toward Israel, and Egyptian Foreign Minister Ahmed Aboul Gheit accused the Security Council of "turning a blind eye to Israeli acts in Gaza."

The Arab League was planning to hold an emergency meeting of foreign ministers in Cairo, Egypt, on Sunday to decide how to respond the latest Israeli offensive.

The draft resolution had been weakened slightly in recent days to help improve its chances of passage. A section was added demanding the Palestinian Authority take immediate action to bring an end to violence, including the firing of rockets into Israel.

It also called for the UN secretary-general to establish a "fact-finding mission" to probe Wednesday's attack in Beit Hanoun, a step below ordering a full investigation. In addition, it backed off calls for UN observers to be placed on the Gaza-Israel border, asking instead for the "possible establishment of an international mechanism for protection of the civilian populations."