U.N. Secretary-General Kofi Annan (search) strongly condemned the killing Monday of Hamas leader Sheik Ahmed Yassin (search), saying it would not help peace efforts in the region and violated international law.
The Palestinian envoy to the United Nations sought an official condemnation from the U.N. Security Council.
Israel assassinated Yassin in a pre-dawn missile attack, touching off protests across the Middle East. The killing prompted the United Nations, United States, Russia and the European Union -- the so-called "quartet" -- to discuss its consequences at talks Monday night in Cairo, Egypt.
"Such actions are not only contrary to international law, but they do not do anything to help the search for a peaceful solution," Annan said at U.N. headquarters in New York. "I appeal to all in the region to remain calm and avoid any further escalation in tensions."
Annan said the killing would only complicate the group's efforts to achieve peace in the Middle East, and urged Israel to end targeted killings.
The Palestinians demanded official condemnation from the Security Council, and the body discussed Yassin's assassination in consultations early Monday.
"We of course condemn this criminal insane act, we notice the broad international condemnation of this extra-judicial execution and also of the practice as a whole," chief Palestinian delegate Nasser Al-Kidwa (search) said. "We think that the Security Council has to live up to its responsibility, it has to reflect this broad international condemnation."
The delegations met later Monday to discuss a proposed text circulated by Algeria, the only Arab nation on the council.
Al-Kidwa said that if there wasn't progress on that text Monday, Arab leaders would demand a new Security Council meeting exclusively focused on the Israeli attack.
The United States, one of five permanent members of the Council, would have to accept such an official statement, a prospect which appears unlikely.