The comments follow a stunning policy reversal this month by Prime Minister Srettha Thavisin, who pledged to re-criminalise cannabis by the end of the year after it was de-criminalised in 2022.
Recreational use will be barred by a new regulation, Somsak said, with a licence required by those who grow, export and possess it for medical and research use, although details of the licensing process were still being worked out.
"The permit system must not place an unreasonable burden on the public," he said in a post on Facebook, adding that there would be a grace period for the public to adjust.
Pro-cannabis groups have protested against Srettha's move, saying it stands to damage business confidence after thousands of cannabis cafes and dispensaries sprang up after legalisation, an industry projected to be worth up to $1.2 billion by 2025.
Thailand has a long tradition of using marijuana to relieve pain and fatigue, and it finds use also in traditional medicine and recipes.
The Southeast Asian country first legalised cannabis for research and medical use in 2018 and two years ago dropped the plant from the national narcotics list, allowing people to grow, sell and consume it.
