U.S. President Joe Biden has called Israel's killing of Hezbollah leader Sayyed Hassan Nasrallah 'a measure of justice' for his victims and expressed full support for Israel's right to defend itself against Iran-supported groups. Biden has directed Defense Secretary Lloyd Austin to enhance the defense posture of U.S. military forces in the Middle East to deter aggression and reduce the risk of a broader war. Israel has rejected global calls for a ceasefire with Hezbollah, defying Washington and continuing strikes that have killed hundreds in Lebanon. Biden aims to de-escalate conflicts in Gaza and Lebanon through diplomatic means.