The Centre for Covid-19 Situation Administration has admitted there is a shortage of vaccine, with no deliveries expected this week.
The admission came after many hospitals announced they would have to postpone scheduled inoculations because of the lack of supply.
Gen Nattapon Nakpanich, who runs the CCSA's day-to-day operations, said on Monday no vaccines were scheduled for delivery this week. However, he remained confident the target of 6 million doses this month would be met.
The National Security Council secretary-general was briefing reporters on the situation at Government House, in company with Bangkok governor Aswin Kwanmuang and Opas Karnkawinpong, director-general of the Department of Disease Control.
The media briefing was ordered by Prime Minister Prayut Chan-o-cha, the CCSA director, after the Bangkok Metropolitan Administration and the Public Health Ministry blamed each other for the scarcity of vaccines.
Only one week after Gen Prayut launched a nationwide inoculation campaign, hospitals have deferred jab appointments for this week, saying they were unable to obtain the vaccines.
The BMA on Monday also announced that the vaccination of Bangkok residents registering on the Thai Ruam Jai scheme would be postponed from Tuesday.
Dr Opas said more vaccines would be distributed to all agencies, but he could not give any accurate timing.
City governor Aswin said Bangkok would resume inoculations as soon as it receives a supply of vaccine from the ministry.