New Delhi: The government is exploring the use of Indian Air Force to transport NEET-UG question papers and identifying secure locations beyond banks to store exam materials as part of a "whole-of-government" approach to ensure foolproof conduct of the June 21 retest, official sources said.The measures were discussed at a high-level meeting chaired by defence minister Rajnath Singh and attended by education minister Dharmendra Pradhan and communications minister Jyotiraditya Scindia.Sources said postal transportation is viewed by some as vulnerable points. Hence, IAF could be involved in the exercise. Sources said the government is working under severe time constraints as the retest is being conducted within 38 days of cancellation of the May 3 exam amid allegations of paper leak.The monsoon season has also emerged as a logistical challenge, with officials citing difficulties in transporting papers to places such as Lakshadweep during adverse weather conditions.Along with banks, authorities are exploring other highly secure locations for storage of examination papers, sources said. The meeting reviewed the entire chain - from setting of question papers by teachers, printing, transportation and storage to security arrangements at centres.No final decision has been taken on the use of Air Force and the proposal is likely to be placed before the PM, who is personally monitoring the preparations, sources said.