The European Council is calling on all EU-based carriers to avoid overflight of Belarus.
Extra sanctions are also being planned after a Ryanair flight was forced to land in the country on Sunday.
The plane was diverted en-route to Lithuania from Greece, after reports it had explosives on board - but none were found.
Belarussian opposition journalist Roman Protasevich and a colleague were then arrested.
At a meeting in Brussels on Monday, the European Council strongly condemned the forced landing in Minsk, as well as the detention of Pratasevich and Sofia Sapega - a 23-year-old student travelling with him.
It also said the incident 'endangered aviation safety.'
The council is demanding the immediate release of Pratasevich and Sapega, and that their freedom of movement be guaranteed.
It is also calling on the International Civil Aviation Organisation to "urgently investigate this unprecedented and unacceptable incident".
And it says further targeted economic sanctions are needed, while asking for proposals on this "without delay".
It is also calling on the council to adopt the necessary measures to ban overflight of EU airspace by Belarusian airlines, and prevent access to EU airports of flights operated by them.
Conclusions on #Belarus adopted at #EUCO chaired by @eucopresident pic.twitter.com/MWco6QEiTy
— Barend Leyts (@BarendLeyts) May 24, 2021
Mr Protasevich earlier appeared in a video released by authorities in Belarus.
In it, he said he was in good health and admitted helping to organise mass protests in Minsk last year.
Wearing a dark top and with his hands tightly clasped in front of him, he added he was in a pre-trial detention facility in the capital and denied having heart problems - which had been reported on social media.
He also appeared to have a dark spot on his forehead.
But his allies have dismissed his comments as being made under duress.
Exiled Belarus opposition leader Svetlana Tikhanovskaya tweeted: "This is how Roman looks under physical and moral pressure. I demand the immediate release of Roman and all political prisoners."
The regime's propaganda channels posted a video of arrested Raman Pratasevich, saying that he is treated lawfully in the Minsk Detention Center №1. This is how Raman looks under physical and moral pressure. I demand the immediate release of Raman and all political prisoners. pic.twitter.com/zdolsbp6m5
— Sviatlana Tsikhanouskaya (@Tsihanouskaya) May 24, 2021
Ryanair said Belarusian flight controllers had told the crew there was a bomb threat against the passenger aircraft as it was crossing through Belarus airspace on Sunday and ordered it to land.
Belarusian authorities at the airport then detained the 26-year-old blogger, who ran a popular messaging app that played a key role in helping organise demonstrations.
Sophia Sapega was also detained, before the aircraft was later allowed to continue its journey to Lithuania.
Earlier, the Russian ambassador to Ireland Yury Filatov said there should not be "any rush to judgement" over the incident.
He told The Hard Shoulder a full investigation needs to be carried out.
He said: "There are many tough words around now - I don't think there should be any rush to judgement.
"There are clear rules which govern the airspace, the air travel under the International Civil Aviation Organisation and Convention.
"And I think that the incident has to be thoroughly investigated by the international aviation authorities", he added.
Additional reporting: IRN
