Assad made the remarks in a meeting with Saeed Jalili, Iran's national security council secretary, in the Syrian capital. It was his first reported response to the attack.
State news agency SANA quoted Jalili as reaffirming Tehran's "full support for the Syrian people ... facing the Zionist aggression, and its continued coordination to confront the conspiracies and foreign projects".
The Syrian president, Shi'ite Iran's closest Arab ally, is battling a 22-month-old uprising in which 60,000 people have been killed. Assad says the rebels are Islamist terrorists funded and armed by Turkey and Sunni Muslim Gulf Arab states.
Neighbouring Israel has said it might have to intervene to prevent Syrian chemical or advanced weapons falling into the hands of militant groups, including Lebanon's Hezbollah whch fought a 34-day war with Israel in 2006.
Diplomats, Syrian rebels and security sources said Israeli jets bombed a convoy near the Lebanese border on Wednesday, apparently hitting weapons destined for Hezbollah. Syria said the target was a military research centre northwest of Damascus.