NEW : United Nations secretary-general expresses `` grave concern '' about airstrike . Iran , Russia and Hezbollah condemn the attack . Syrian reports that strike hit research center are wrong , U.S. official says . World leaders seeks $ 1.5 billion for afflicted Syrians . Comment:
NEW : United Nations secretary-general expresses `` grave concern '' about airstrike . Iran , Russia and Hezbollah condemn the attack . Syrian reports that strike hit research center are wrong , U.S. official says . Comment: