US President Joe Biden has joined the condemnation of Belarus after it scrambled a warplane to intercept a Ryanair passenger jet to arrest dissident journalist Roman Protasevich.

Mr Biden described the incident as “outrageous”, while Irish Foreign Minister Simon Coveney denounced the move as “effectively aviation piracy, state sponsored.”

As the US joined calls for an international investigation on Monday, Mr Biden said the diversion of the plane to arrest Protasevich, 26, was “a direct affront to international norms”.

The EU has already imposed sanctions against Belarus, including banning its airlines from using the airspace and airports in the bloc.

Mr Biden also expressed outrage over a video statement from the detained journalist, claiming the blogger’s taped confession was made “under duress”.

In the video posted online, Protasevich said his treatment in custody was “maximally correct and according to law” and said he was in good health.

He added he was giving evidence to investigators and acknowledged having played a role in organising mass disturbances in the capital last year.

However, Polish deputy foreign minister Pawel Jablonski told broadcaster TVN24 his government had heard from Protasevich’s mother that he was in poor health despite Belarus officials claiming he had not complained of ill health.

In the Telegram video, Protasevich wore a dark sweatshirt and clasped his hands tightly in front of him.

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Protasevich ran a popular messaging app that played a key role in helping organise massive protests against Belarus authoritarian leader President Alexander Lukashenko, which aired on Belarusian state television on Monday night local time.

“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.”

• Related: International outrage after Belarus forces plane to land
• Related: Belarus blames Hamas bomb threat for forced landing

Separately, the White House said that national security adviser Jake Sullivan on Monday spoke with Belarus opposition leader Svyatlana Tsikhanouskaya.

Mr Sullivan told her the US “in co-ordination with the EU and other allies and partners, will hold the Lukashenko regime to account”.

Protasevich’s social media feed from exile has been one of the last remaining independent outlets for news about Belarus since a mass crackdown on dissents last year.

Sofia Sapega, a 23-year-old student travelling with him, was also detained.

NEXTA, a news service where Protasevich worked before setting up his own widely followed blog, ran an interview with his mother.

She said that as soon as she heard reports of a bomb scare on a flight, she knew it was a plot to capture him.

“I just want to say that my son is simply a hero, simply a hero,” Natalia Protasevich said, weeping.

“I truly hope that the international community will wake up for him.”

Protesters rallied against the detention of the Belarusian journalist Protasevich in Warsaw, Poland on May 24. Photo: Getty

EU leaders meeting in Brussels on Monday local time called for Belarusian airlines to be banned from the bloc’s airspace and urged EU-based carriers to avoid flying over the former Soviet republic.

They also agreed to widen the list of Belarusian individuals they already sanction and called on the International Civil Aviation Organisation (ICAO) to urgently investigate the forced landing incident.

Britain said it was instructing its airlines to cease flights over Belarus and that it would suspend the air permit for Belarus’s national carrier Belavia with immediate effect.

KLM, the Dutch arm of carrier Air France KLM, would temporarily halt flights, Dutch news agency ANP reported.

German airline Deutsche Lufthansa later said it would avoid Belarusian airspace until further notice.

Still, the options for Western retaliation appear limited.

The Montreal-based ICAO has no regulatory power, and the EU has no authority over flights taking off and landing in Belarus or flying over its airspace, apart from direct flights that originate or land in Europe.

Belarus lies on the flight path of routes within Europe and between Europe and Asia, and skirting Belarus would slow flights down and cost airlines money.

The EU and the United States imposed several rounds of financial sanctions against Minsk in 2020, which had no effect on the behaviour of Mr Lukashenko, who withstood mass demonstrations against his rule after a disputed election.

Since the disputed vote, authorities rounded up thousands of his opponents, with all major opposition figures now in jail or exile.

Belarus maintains it acted in response to a false bomb threat by Palestinian militant group Hamas. A Hamas spokesman denied the group had any knowledge or connection to the matter.

Belarus said its ground controllers had given guidance to the flight but had not ordered it to land. State media said the intervention was ordered personally by Mr Lukashenko.

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 never arrived, suggesting three others besides detainees Protasevich and Ms Sapega had disembarked in Minsk.

Russia, which has provided security, diplomatic and financial backing to Mr Lukashenko, accused the West of hypocrisy.

-with AAP