The last of Syria's declared chemical agents have been shipped from the war-torn country after months of delays and are en route for destruction at sea, the world's chemical watchdog said.

United Nations Secretary-General Ban Ki-moon welcomed the news Monday and said the successful completion of such a tricky exercise showed that, when there was the political will, "there can be progress towards peace".

NATO foreign ministers convene Tuesday to discuss the Iraq crisis after U.S. Secretary of State John Kerry pledged "intense" support to Baghdad in the fight against militants pushing towards the capital.

Kerry made a surprise visit to Iraq on Monday as Sunni insurgents led by the jihadist Islamic State of Iraq and the Levant, or ISIL, seized a strategic town in the northern part of the country, while security forces retook a border crossing with Syria.

At least 2,400 Tunisian jihadists are fighting in Syria, most of them rebels affiliated to the radical Islamic State of Iraq and the Levant (ISIL), Tunisia's interior minister said Monday.

"According to what we have gathered, there are 2,400 Tunisians who have gone to Syria to fight with al-Nusra Front and the majority of them -- 80 percent -- with (ISIL)," Lotfi Ben Jeddou told reporters, without specifying his source.

Convinced they would be able return to Yarmuk in southern Damascus after a truce and ceasefire, Palestinians went to the embattled camp's entrance Monday but their wait was in vain.

"I heard about the deal so I bought food because I thought I could go home, but (the regime forces) did not let me go because armed men still haven't left," said a 30-year-old woman clutching a bowl of eggs.

Russia on Monday hailed the "successful" completion of an international mission to ship chemical agents out of Syria, under a U.S.-Russia brokered agreement that helped avert the threat of Western air strikes.

"Russia greets the successful end of a large-scale and unprecedented international operation to ship all components of chemical weapons and their precursors out of Syria with deep satisfaction," the foreign ministry said in a statement.

Russian President Vladidmir Putin and his U.S. counterpart Barack Obama on Monday expressed "serious concern" over the advances of jihadists from the Islamic State of Iraq and the Levant (ISIL) in Iraq.

"The Russian leader expressed support for Baghdad's efforts in the fight against Islamists and bringing about peace and stability in the country," said the Kremlin statement after phone talks between to two rivals, adding the two leaders also discussed Syria and Iran's nuclear program.

Fifteen Syrians wounded in battles in Syria's Qalamun region were evacuated Monday to hospitals inside Lebanon.

“Fifteen Syrians injured in Qalamun's battles were transferred by the Lebanese Red Cross via the (Bekaa) town of Arsal to hospitals in Tripoli and western Bekaa,” Lebanon's National News Agency reported.

Syria urged the United Nations on Monday to condemn Israel's "flagrant violation" of its territory over air raids it said killed four of its soldiers in the Israeli-held Golan Heights.

"The Israeli occupation forces on Sunday and Monday carried out a new attack against positions inside Syrian territory, which constitutes a new, flagrant violation of the 1974 Separation of Forces Agreement, of the U.N. charter and international law," Syria's foreign ministry said in letters addressed to the U.N. secretary general and to the Security Council.

The last of Syria's declared chemical agents have been shipped from the war-torn country after months of delays and are en route for destruction at sea, the world's chemical watchdog said on Monday.

"As we speak, the ship (carrying the last chemicals) has just left the port (of Latakia)," Ahmet Uzumcu, head of the Organization for the Prohibition of Chemical Weapons, told journalists in The Hague where the OPCW is based.

Progressive Socialist Party leader MP Walid Jumblat urged on Monday Lebanese officials to put aside all political differences and seek to unify their stances to confront the “dangerous developments.”

“It's a crucial need more than ever to overcome all the acute political differences and unite our perspective to face the dangerous and swift developments before we regret it and it becomes too late,” Jumblat said in his weekly statement to al-Anbaa website.