The UN has “grave” concerns over Israel’s reported strike on sites inside Syria, Secretary General Ban-Ki-moon said in a statement Sunday.

The secretary general reacted Sunday to Israel’s reported airstrikes against Syria over the last three days, stating that he was highly “concerned” over the recent developments in the region.

Ban called on both Israel and Syria to “exercise maximum calm and restraint, and to act with a sense of responsibility to prevent an escalation of what is already a devastating and highly dangerous conflict.”

“The Secretary-General expresses grave concern over reports of air strikes in Syria by the Israeli Air Force,” read an official statement issued by his office.

The Sunday statement was the UN’s first official response to the attacks since they were first reported late Friday.

Ban also urged Syria and Israel to “respect national sovereignty and territorial integrity of all countries in the region,” and to “adhere to all relevant Security Council resolutions.”

According to unnamed Israeli and American sources, Israeli planes struck sites outside Damascus early Friday and again early Sunday, targeting weapons transfers from Iran to Hezbollah.

In Washington, diplomatic sources and US officials told NBC that the administration fully supported the Israeli move.

An Israeli official told the Los Angeles Times that both strikes were carried out to thwart weapons transfers from Iran to Hezbollah, which would have given the Lebanese terror group a new missile capability.

“We are not taking sides and we’re not interested in interfering in the internal affairs of Syria,” the senior official said. “But we have to make sure these weapons do not fall into the hands of Hezbollah, because the minute that happens it will be hard to track and monitor them. That’s the only reason we interfered. If we don’t take action now, we will be on the receiving end of those missiles. We have to act to guarantee our security, and that applies to Syria and Iran.”

Channel 10 described major explosions at the Jamraya research center near Damascus, as well as blasts at military bases on Mount Qassiyoun and near Assad’s presidential palace. It said the strikes early Sunday were targeting missiles from the same Iranian shipment hit on Friday — a consignment of the latest generation of Iranian-made Fateh-100 surface-to-surface missiles (also known as M600s) that arrived in Syria last week. These missiles carry 600-kilogram warheads, have a 300-kilometer range, and are accurate to 200 meters, the TV report said.

Israel on Sunday deployed two Iron Dome anti-missile batteries, in Safed and Haifa, and Haifa Mayor Yonah Yahav ordered preparations in his city for the possibility of Syrian retaliation. Israel also closed off its airspace in the north for the first time since the 2006 Lebanon War, halting civilian flights to and from Haifa’s airport through Thursday.

However, officials said they did not believe Syria would respond immediately, though Hezbollah might lob missiles from southern Lebanon in retaliation.

Earlier Sunday, Egypt, Lebanon and the Arab League called on the international community to take steps in order to prevent further attacks on Syrian soil. Condemnations by Arab countries emphasized Israel’s “aggression” and stressed disapproval at Jerusalem’s lack of respect for war-torn Syria’s sovereignty.

Also Sunday, Iranian army ground forces commander Ahmad Reza Pourdastan said Tehran was ready to support Syria and offer it aid in case of further Israeli strikes.

“Syria has a powerful army and with the structure and experience it has against the Zionist regime it can definitely defend itself and there is no need for intervention by other countries,” said Pourdastan, according to the Iranian Fars News Network. “But, if they do need training, we can help them,” he added.

In Syria, Deputy Foreign Minister Faisal Mekdad warned Sunday that recent Israeli airstrikes on facilities near Damascus constituted an Israeli “declaration of war.”