The convoy arrived at the Reyhanli district on the border, the agency reported.
Turkey expanded the Atmeh refugee camp on the Syrian side of the border and reinforced its 12 observation stations in Idlib ahead of the looming battle.
The United Nations worries the offensive could force 2.5 million people toward the Turkish border. The area, controlled by rebels since 2015, has been a target of airstrikes by the government and Russia for months.
U.N. special envoy for Syria Staffan de Mistura met senior officials from Turkey, Russia, and Iran, the body intended to draft a new Syrian constitution, on Sept. 10.
On July 5, the Syrian Negotiation Commission submitted a list of 50 candidates to represent the Syrian opposition in the constitutional committee to de Mistura.
The meeting held under the U.N. umbrella to end the seven-year-old civil war in Syria consists of four titles including transition, constitution, elections and fight against terrorism.
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