Hasan Shibly, a spokesman for the "Freedom Convoy" group, said Wednesday that the activists will try to cross the border Thursday to take truckloads of food, medical aid and other supplies into Syria.
Shibly says the group - consisting mostly of Syrians traveling from Bulgaria, The Netherlands, France and the United States - would camp near the border in a three-day sit-in protest if Syrian authorities refuse to let them cross.
The group said plans for a similar mission from Jordan into Syria have been canceled.