UN Secretary General Kofi Annan has urged world leaders to agree on a universal definition of terrorism. The bomb attacks in London and Egypt underscored the need for a definition with "moral clarity" and a UN convention against terrorism, he said. A UN treaty has been stalled for years over the definition of a terrorist. A new UN proposal calls terrorism any act intended to intimidate a population or to compel a government or an international body to act. "The targeting and deliberate killing of civilians and non-combatants cannot be justified or legitimized by any cause or grievance," it adds. Annan wants the proposed UN terrorism convention to be agreed on by world leaders in time for a UN world summit in September. "A simple, clear statement bringing in moral clarity that maiming and killing of civilians is unacceptable regardless of one's cause I think will satisfy all of us," he added. The proposed convention has been stuck in a committee since 1996. The debate has focused on the Palestinian-Israeli conflict. Arab League Secretary General Amr Moussa backed Annan's latest definition, telling Reuters news agency that it could serve as the "basis for consensus". However, "resisting occupation is a different issue altogether", he said. --MORE 1514 Local Time 1214 GMT