The United Nations suspended land deliveries after the convoy attack, which the Syrian Arab Red Crescent says killed a staff member and around 20 civilians.
US officials believe Russian aircraft were responsible for the strike, but Moscow has denied involvement and the Russian Defence Ministry said on Wednesday a US Predator drone was in the area when the convoy was attacked.
Elizabeth Hoff, the World Health Organisation (WHO) representative in Syria, told Reuters on Wednesday that the UN health agency planned to deliver medical supplies on Thursday to the rebel-held besieged Damascus suburb of Moadamiya, subject to the normal security risk assessments.