Any attempt to regulate exports could further slow vaccine rollout to Malaysia, Vietnam and Indonesia, which are also battling spikes in infections and supply disruptions caused by earlier export curbs imposed by India.
The move also marks a fresh setback to AstraZeneca, which had initial delays in regional production and delivery and hoped to put it back on track from this month and meet its supply commitments to the region.
Nakorn Premsri, a key member of the National Vaccine Committee, told reporters when asked about a plan to place a quota on vaccine exports that the committee had "agreed in principle" on such a draft order.
"Right now, the order has not been issued yet," Nakorn said, adding that various agencies will need to review it and consider its impacts.
He did not address at what levels export quotas might be set.
Thailand is suffering its worst coronavirus outbreak yet, with hundreds of deaths in recent weeks and more than 8,000 new infections reported on many days this month - and only about 5 percent of its more than 66 million population is fully vaccinated.
AstraZeneca said in a statement its Thailand-manufactured vaccine "is of critical importance" to neighboring countries where the pandemic is also accelerating.
"We are actively working with the government in Thailand and governments across Southeast Asia to continue to deliver equitable vaccine access to the region," the statement said.
In late June, AstraZeneca Thailand said its partner Siam Bioscience, owned by King Maha Vajiralongkorn, would produce 180 million doses this year, just over a third for Thailand and two thirds for elsewhere in Southeast Asia.
"Right now we will talk with the vaccine manufacturer so they can deliver the vaccine to Thailand in a suitable manner that matches the outbreak situation in the country," Nakorn told reporters.
AstraZeneca delivered 6 million doses, as promised, to Thailand in June when the country's mass vaccine rollout started. A Thai official last month said a similar volume would be delivered in July, short of the previously announced 10 million monthly doses.
Thailand's government has so far used the AstraZeneca's viral vector vaccine and Sinovac inactivated virus vaccine.