Hezbollah chief Hassan Nasrallah vowed to keep his forces in Syria where they are fighting alongside President Bashar al-Assad's regime, in a rare public speech delivered in Beirut on Thursday. "We have said on several occasions that the presence of our soldiers on Syrian soil is to defend... Syria, which supports the resistance" against Israel, said the Lebanese Shiite leader. "Our presence there is justified," he told hundreds of thousands marking a Shiite commemoration in south Beirut, in his second public appearance in as many days.