French President Emmanuel Macron said he would like the Belarusian opposition to be invited to the G7 summit in Britain next month after the family of jailed journalist Roman Protasevich accused the regime of torture.
European leaders retaliated for an act of "state piracy" by Minsk in forcing the Ryanair plane carrying Protasevich into an unscheduled stop.
The EU banned Belarusian airlines from its airspace and advised carriers not to fly over the country.
German Foreign Minister Heiko Maas on Tuesday said Belarusian President Alexander Lukashenko would pay for the "heinous" flight diversion that led to Protasevich's arrest.
"Any dictator toying with such ideas must be made to understand that they will pay a bitter price," Mr Maas said in Berlin, a day after EU leaders agreed to cut air links and impose more economic sanctions.
"Our goal has always been to hit Lukashenko and his power apparatus with these measures, not the civilian population, which is already suffering enough under this regime."
Canada on Tuesday condemned Belarus and said it was considering more sanctions.
"The behaviour of the Belarus regime is outrageous, illegal, and completely unacceptable," Prime Minister Justin Trudeau said.
"We also condemn this kind of dangerous interference in civil aviation."
The Belarus embassy in Ottawa, Canada, said it would shut down on September 1 after 24 years. It did not give details and no one at the mission was immediately available for comment.
A video emerged of Protasevich, 26, apparently confessing to organising mass protests last year against Mr Lukashenko.
In his short statement, which appears scripted, he said he was being treated correctly and was co-operating with investigators.
His father, Dzmitry Protasevich, said he did not believe his son would have confessed voluntarily and he was worried for his safety.
“It’s likely his nose is broken because the shape of it has changed and there’s a lot of powder on it," Mr Protasevich said. "All of the left side of his face has powder.
“It’s not his words, it’s not his intonation of speech. He is acting very reserved and you can see he is nervous.
"My son cannot admit to creating the mass disorders because he just didn’t do any such thing.”
Mr Protasevich said he was “really afraid” for his son’s safety in the hands of Belarusian authorities.
“I think what happened was an act of revenge, to enlighten others: 'Look what we can do',” he said. “This is total insanity, what is going on.”
UK Prime Minister Boris Johnson said the video made for "distressing viewing" and Belarus would face consequences.
Meanwhile, the country's exiled opposition leader Sviatlana Tsikhanouskaya said the footage proved Protasevich had been tortured.
"He said that he was treated lawfully, but he's clearly beaten and under pressure," Ms Tsikhanouskaya said.
"There is no doubt that he was tortured. He was taken hostage."
Belarus did not immediately comment on the torture allegations but has consistently denied abusing detainees.
Rights groups, however, have documented hundreds of cases of what they call abuse and forced confessions during a crackdown on pro-democracy activists since last year.
France and Ireland described the incident as piracy, while Nato Secretary General Jens Stoltenberg called it a "state hijacking".
London did not immediately respond to Mr Macron's proposal for a focus on the Belarus opposition at the June 11 to 13 summit of the top economic powers.
Earlier, EU leaders urged all bloc-based carriers to avoid flying over Belarus, imposed sanctions on officials linked to the flight diversion and urged the International Civil Aviation Organisation to start an investigation.
They called for Minsk authorities to release of Protasevich and his Russian girlfriend, Sofia Sapega, who was taken from the plane with him.
The text was endorsed quickly by the leaders who were determined to respond with a “strong reaction” because of the “serious endangering of aviation safety and passengers on board by Belarusian authorities”.
Airlines avoided Belarusian airspace on Tuesday in response to the EU demand.
European Council President Charles Michel accused the regime of playing with people’s lives.
“We won’t tolerate that one can try to play Russian roulette with the lives of innocent civilians,” Mr Michel said.
At least one European airline had diverted a flight around Belarus in response to advice from the UK government.
British Airways Flight 3599, which crossed over Belarus on Saturday and Sunday, bypassed the country on Monday by using Russian airspace, according to Flightradar24.
Lufthansa, KLM, SAS, Air France, LOT and Singapore Airlines also announced they would stop flying over Belarus.
Mr Michel tweeted a photograph of empty airspace over Belarus on Tuesday with the words: "Europe in action."
Ryanair said Belarusian flight controllers told the crew there was a bomb threat against the plane as it was crossing through Belarus airspace on Sunday, and ordered it to land.
A Belarusian MiG-29 fighter jet was sent to escort the plane in a show of force by Mr Lukashenko, who has ruled the country with an iron fist for more than a quarter of a century.
Belarus authorities then arrested the activist, journalist and prominent Lukashenko critic.
Authorities have not said where Protasevich and his partner are being held.
Ryanair Flight FR4978, which began in Athens, Greece, was eventually allowed to continue to Vilnius, Lithuania.
Ryanair boss Michael O’Leary, who referred to the incident as a “state-sponsored hijacking”, said he believed security agents had been on the flight.
Lithuanian authorities said five passengers did not arrive, suggesting three others besides Protasevich and Ms Sapega disembarked in Minsk.
Russia, which has provided security, diplomatic and financial backing to Mr Lukashenko, accused the West of hypocrisy.
But European Commission President Ursula von der Leyen accused the Belarusian regime of launching “an attack on democracy”.
“This is an attack on freedom of expression. And this is an attack on European sovereignty. And this outrageous behaviour needs a strong answer,” Ms von der Leyen said.
She said a €3 billion ($3.67bn) EU investment and economic package for Belarus would remain on hold until it “turns democratic”.
US President Joe Biden said he had asked his team to develop appropriate options for holding those responsible to account.
“This outrageous incident and the video Mr Protasevich appears to have made under duress are shameful assaults on both political dissent and the freedom of the press,” Mr Biden said.
“The United States joins countries around the world in calling for his release, as well as for the release of the hundreds of political prisoners who are being unjustly detained by the Lukashenko regime.”
Former US ambassador to Nato, Kurt Volker, said people should not be fooled by the apparent confession video.
“It reminded me of all the hostage tapes we’ve seen terrorists release from the Middle East where they have someone in captivity,” Mr Volker told BBC’s Radio 4.
He said the problem for the EU would be how to stop Belarus from “the trajectory they are on” without further pushing them further into the hands of Russia.
EU leaders have tried to bring Belarus closer to the bloc to encourage democratic reforms and reduce the influence of Russia, but have failed.
On Monday, UK Transport Secretary Grant Shapps said he had told the UK Civil Aviation Authority “to request airlines avoid Belarusian airspace in order to keep passengers safe”.
Mr Shapps said he was suspending Belavia Belarusian Airlines’ permit to operate in the UK.
Irish Foreign Minister Simon Coveney said: “This was effectively aviation piracy, state sponsored”.
The Belarusian Foreign Ministry was angered at “belligerent” EU statements and insisted that Minsk acted “in full conformity with international rules”.