Jordan closed its main border crossing with Syria on Monday after two days of fighting there between Syrian troops and rebel fighters, Jordan's information minister said. "The border post is effectively closed because there have been clashes since yesterday and they are continuing," Minister Samih al-Maaytah said. Arab media outlets quoted officials in Jordan as saying that the move stemmed from the deteriorating situation around the border shared by Jordan, Syria and Israel: Syria's southern Deraa province, located just off the Jordanian border, is a vital battleground between the rebels and the Syria Army. The rebels have stepped up fighting for control of the border area, after gaining territory in the countryside and capturing several army bases. They have also overrun several towns near the Golan Heights, fueling tensions in the sensitive military zone. Israel Hayom reported on Monday that the Jordanians were concerned about the situation on the border as Syrian President Bashar al-Assad's regime continues to topple. Twenty-four hours later the decision to close the border was made final. A Jordanian defense official explained that "after the disintegration of Assad's divisions, the territory is now controlled by militias and terrorists." Fighting continued to rage in Syria with dozens reported killed each day. Members of the Syrian opposition accused the regime's intelligence branch of attempting to assassinate the deputy commander of the Free Syria Army during his visit to rebel forces in northern Syria. Meanwhile, to applause from Arab heads of state, a foe of Assad took Syria's vacant seat at an Arab summit on Tuesday, deepening the president's diplomatic isolation and diverting attention from rifts among his opponents. Speaking at an annual gathering of Arab leaders in the Gulf state of Qatar, Moaz al-Khatib, the recently resigned president of the National Coalition for Syrian Revolutionary and Opposition Forces, said he had asked U.S. Secretary of State John Kerry for American forces to help defend rebel-controlled northern parts of Syria with Patriot surface-to-air missiles now based in Turkey. NATO swiftly rebuffed the idea. Khatib also called on Arab nations to defend Syrian civilians. "It was a historic meeting," said Syrian opposition spokesman Yaser Tabbara. "It's a first step towards acquiring full legal legitimacy." The 22-nation league lent its support to giving military aid to Syrian rebels. A summit communiqu offered some of its toughest language yet against Assad, affirming member states had a right to offer assistance "including military, to support the steadfastness of the Syrian people and the Free Army". Khatib said the United States, which has given non-military aid to Syrian rebels, should play a bigger role in helping end the two-year-old conflict in Syria, blaming Assad's government for what he called its refusal to solve the crisis. "I have asked Mr. Kerry to extend the umbrella of the Patriot missiles to cover the Syrian north and he promised to study the subject," he said, referring to NATO Patriot missile batteries sent to Turkey last year to protect Turkish airspace. "We are still waiting for a decision from NATO to protect people's lives, not to fight but to protect lives," he added, addressing a body that barred Assad's government in late 2011. Responding to Khatib's remarks, an official of the Western military alliance at its headquarters in Brussels said, "NATO has no intention to intervene militarily in Syria." Turkey, which reported a mortar landing harmlessly on its border on Tuesday, said it was up to the rest of NATO to decide if members wanted to expand the remit of the Patriot batteries. Michael Stephens, a researcher based in Qatar for Britain's Royal United Services Institute, said acceding to Khatib's request would effectively put NATO at war with Damascus. Meanwhile, The New York Times reported that the CIA was helping Turkey and Arab nations ramp up their arms transfers to the Syrian opposition. Israel Defense Forces Chief of Staff Lt. Gen. Benny Gantz said in an interview that Israel's front with Syria is "a bit more sensitive than it has been in the past, but as of now I don't foresee any escalation."