Hungary aligned itself with Turkey, which had long blocked Sweden's membership before lifting its veto in July, and has still not voted to approve the country's entry into the North Atlantic Treaty Organisation.
Mr Orban has repeatedly stated in the past that Hungary supports Sweden's bid, stressing that it was merely a "technicality".
"I wonder if there is something urgent that would force us to ratify Sweden's Nato bid. I cannot see any such circumstance," he told politicians.
Mr Orban underpinned his remarks by saying that there was "no threat to Sweden's security" and no military relationship with the Nordic country that could be jeopardised.
Budapest has often denounced what it called Stockholm's "open hostile attitude", accusing Swedish representatives of being "repeatedly keen to bash Hungary" on rule-of-law issues.
In recent weeks, criticism increased after a video from 2019 resurfaced that allegedly shows the democratic decline in Hungary.
Nato through the years - in pictures
"Serious accusations and fake informations are being spread to students in the schools of Sweden," Hungarian Foreign Minister Peter Szijjarto wrote in a letter sent to his Swedish peer in mid-September.
The video about Hungary being shown in schools "elevates the problem … to the level of international policy, and we will not accept that", Mr Orban said on Monday.
Finland and Sweden ended decades of military non-alignment and decided to join the alliance after Russia's invasion of Ukraine.
In April, Finland became the 31st member of Nato.