USA airstrikes blocked the advance of an Islamic State convoy carrying militants toward Iraq on Wednesday, derailing a Hezbollah-negotiated deal that removed the extremists from the Lebanon-Syria border, where they have been for years.
Lebanese, Syrian and Hezbollah forces agreed ceasefires with IS militants near the town of Ras Baalbek last week, only days after launching simultaneous offensives on the jihadists' final foothold in the border area.
They are being relocated to Al Bukamal on the Iraq-Syria border in eastern Deir ez-Zor province, part of the middle Euphrates River valley, home to the largest concentration of ISIS militants in Iraq and Syria.
"We have obvious concerns, however, for any action that provides ISIS capabilities to shift its forces and thus put more civilians in harm's way", said Edgar Vasquez, a regional spokesman for the U.S. State Department.
The group, which has been classified as a terrorist by the USA since it was founded following Israeli occupation of Lebanon in the 1980s, has grown in prominence following its victory in 2006 war with Israel.
Iraqis have denounced a Hezbollah- and Syria-backed deal allowing ISIL fighters to evacuate a Syrian-Lebanese frontier region towards the Iraqi border.
Lebanon's security chief Abbas Ibrahim defended the ceasefire agreement on Monday saying security forces were not seeking revenge or bloodshed, but had set out to "liberate" Lebanese soil from IS militants and reveal the fate of the kidnapped soldiers.
According to the deal, around 600 terrorists and family members have now left Lebanon and crossed the border into eastern Syria.
Iraqi Prime Minister Haider al-Abadi said his government has sought an explanation from Syria. "We are monitoring them in real time". "The US-led Coalition realizes what Mr Assad's game is: to move ISIL fighters to the Syrian-Iraqi border region because the regime knows that the Americans will get there first" Mr Heras told The National.
Army commander Gen. Joseph Aoun told reporters later Wednesday that as the army offensive against IS was ongoing, the Lebanese mediator called him to say that the extremists accepted a cease-fire in return for information about the fate of the soldiers.
"I had one of two choices".
His comments came in a speech in which he declared Hezbollah victory in the war against ISIS on the Leabanese border with Syria.
"During our incursions, we try to open safe passages for them so they would not be a target of our attacks, but there are also many mines that led to the deaths of civilians", she said. "While the regime and its allies are trying to frame the Coalition campaign against ISIL in Syria as illegal and unnecessary, the Coalition is pushing back and saying by cutting this deal with ISIL, Mr Assad and his allies, especially Russian Federation, have no moral ground to stand on".