The United Nations said the convoy of more than 100 trucks was carrying food, sanitation and hygiene supplies and health assistance to the camp.
“Conditions at Rukban are increasingly desperate. The vast majority of people at the site are women and children who have been staying there for more than two years in harsh conditions,” said Fadwa AbedRabou Baroud, a UN Damascus-based spokeswoman, Reuters reported.
The Syrian Arab Red Crescent is also taking part in the convoy, which will involve an emergency vaccination campaign for 10,000 children against measles, polio and other diseases.
Rukban, located close to the Al-Tanf US military base in the desert near where the borders of Syria, Jordan and Iraq converge, is home to 40,000-50,000 people. The last UN aid convoy arrived there in November.