A senior Iranian security official visiting Damascus on Saturday pledged Tehran's full support for the Syrian regime, its close ally, Syrian state television said.
"We will give all our support so that Syria remains firm and able to face all the arrogant (Western) conspiracies," said Saeed Jalili, who heads the Supreme National Security Council.
"The Israeli aggression and arrogant international forces have tried to take revenge by attacking the resisting Syrian people," said Jalili, who said Israel and the West had turned "desperate."
Jalili was referring to an alleged Israeli air strike on Wednesday that a US official said hit a military complex and missiles near the Syrian capital.
The Syrian army said the raid, which the Jewish state has not confirmed or denied, targeted a military research centre located between Damascus and the Lebanese border.
On Thursday, Iranian Deputy Foreign Minister Hossein Amir Abdollahian warned that the attack would "have grave consequences," without elaborating.
Israel fears Syrian weapons could be sent to the powerful Lebanese Shiite group Hezbollah, a close ally of Damascus and Tehran.
Jalili said "the Arab and Muslim worlds must do all they can to diminish the Syrian people's suffering because Syria is at the forefront of the struggle against Zionist aggression."
In a separate statement carried by state news agency SANA, he criticised "Syria's enemies who aim to undermine the resistance...by attacking Syria's infrastructure and by pursuing their economic sanctions."
"The Muslim world will not allow an attack against Syria," Jalili warned.
Jalili, who last visited Damascus in August, met with Syrian Prime Minister Wael al-Halqi and discussed "cooperation in the economic, fuel and electricity sectors", SANA said.
Jalili also met on Saturday with national reconciliation minister Ali Haidar, and was due to also hold talks with President Bashar al-Assad and Foreign Minister Walid al-Muallem, Iranian officials in Damascus told AFP.
Jalili is Iran's top nuclear negotiator and a close aide to supreme leader Ayatollah Ali Khamenei.
Iran has backed Assad's accusation that the 22-month uprising against his regime is politically, financially and militarily backed by the United States, Turkey, Saudi Arabia and Qatar.
Washington, in turn, has accused Iran of stepping up military aid to Syria.