He also said the coalition would help ensure they "can never enter Iraq".
The top USA envoy for the worldwide coalition against IS, Brett McGurk, tweeted on Wednesday that IS "terrorists should be killed on the battlefield, not bused across #Syria to the Iraqi border without #Iraq's consent".
A deal between Lebanon and the Islamic State militant group (ISIS), brokered by the country's Shiite militant group Hezbollah, has provoked anger in Baghdad and among Iraqi Kurds after hundreds of jihadis were bussed to the Iraqi border.
The U.S. -led coalition said Wednesday it struck a roadway being used by a Daesh convoy fleeing to territory it controls.
The U.S. government however may not let the deal go through if it has anything to do with it.
"The coalition, we are not party to this agreement between Lebanon, Hezbollah and ISIS", he said. There are about 300 militants and nearly as many family members on buses being evacuated under the deal.
Having pushed into the city in June after months of encircling it, the SDF alliance of Kurdish and Arab militias is fighting in the heart of Raqqa, assisted by air strikes and special forces from the US-led coalition. The buses were escorted by the Syrian army across government-controlled territory on Tuesday, heading to eastern Syria, near the Iraqi border.
"Irreconcilable ISIS terrorists should be killed on the battlefield and not bused across Syria to the Iraqi border without Iraq's consent".
Cabrera, Ausmus, Wilson suspended for fight in Yankees-Tigers game
Robertson would walk the next batter and give up a bases clearing double to Jose Iglesias , giving the Tigers a three run lead. Cabrera said he was punched in the pile by Sanchez, Yankees outfielder Aaron Judge and others.
Brett McGurk insisted that "terrorists should be killed on the battlefield".
Having ousted IS, the Lebanese army on Tuesday deployed across the area, planting its flag near the border, footage on Hezbollah's al-Manar TV showed. Once IS extremists were squeezed over the week end in a small part of the border area they agreed to a cease-fire.
Lebanon has defended the agreement, in which the militants are said to have revealed the location of the remains of nine Lebanese soldiers who were captured in 2014. Shortly afterward, the remains of eight soldiers were located and exhumed in an area near the border with Syria.
The Lebanese soldiers were among 30 troops and police kidnapped by Daesh and terrorists linked to al-Nusra Front, a former affiliate of al-Qaeda, in August 2014 when they briefly overran the Lebanese border town of Arsal.
Lebanese President Michel Aoun declared victory against IS on Wednesday and praised the Lebanese army for carrying out the operation.
"I had two choices: either I continue the battle and not know the soldiers' fate, or I submit to the situation and find out. Their souls are my responsibility", he told reporters.
In the Syrian capital Damascus, President Bashar Assad received Iranian Deputy Foreign Minister Hossein Jaberi Ansari who is on a visit to Syria. State media gave no further details. "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".