On Sunday, Roman Protasevich, 26, was detained after his flight from Athens was diverted from its intended destination of Vilnius, Lithuania.
According to Belarusian state media, the plane was diverted to Minsk after a bomb threat, and Belarusian President Alexander Lukashenko personally ordered a MiG-29 fighter jet to accompany the flight.
Opposition parties, on the other hand, say that the flight was "hijacked" by Belarusian special forces in order to apprehend Mr. Protasevich.
President Lukashenko's government has been accused of endangering the lives of those on board the plane by US Secretary of State Antony Blinken, who has requested a "full investigation."
"We condemn the Lukashenka regime's rash and disturbing decision to divert a commercial flight and detain a journalist. We seek an international investigation and are discussing the next steps with our allies. He tweeted, "The United States stands with the citizens of Belarus."
The incident, according to NATO Secretary-General Jens Stoltenberg, was "serious and dangerous" and "needs an international investigation."
Later today, EU leaders will meet to discuss potential responses to the incident.
President Gitanas Nauseda of Lithuania said he would recommend banning Belarusian planes from European Union airports, as well as "strong sanctions" against Mr. Lukashenko's government for a "state-sponsored terror act."
Ursula von der Leyen, the president of the European Commission, requested Mr. Protasevich's immediate release and said those responsible for "the hijacking must be sanctioned."
"EU inaction would be taken as weakness by Belarus," said Simon Coveney, the foreign minister of Ireland, where Ryanair is based.
"Reports of the detention of NEXTA journalist Roman Protasevich and the circumstances that led to his flight being forced to land in Minsk worried the UK," Foreign Secretary Dominic Raab said.
"We're working together with our allies." Lukashenko's bizarre behavior will have significant consequences."
Travel bans and asset freezes have already been placed on nearly 90 Belarusian officials, including Mr. Lukashenko, by the United States, the European Union, the United Kingdom, and Canada.
That move came after Mr. Lukashenko's victory in Belarus' election in August, which opponents claimed was marred by widespread fraud.
Mr. Protasevich, who now works for Telegram channel Belamova, is wanted in Belarus on charges of inciting social hostility and organizing mass disturbances.
The allegations stem from anti-government demonstrations that occurred after the contested election, which he denies.
According to flight-tracking website FlightRadar24, the Ryanair flight from Athens was diverted just minutes before crossing into Lithuanian airspace.
Belarus informed the plane's crew of a possible security threat on board and ordered them to divert to the nearest airport, Minsk, according to Ryanair.
The plane took off after seven hours in Minsk and safely landed in Vilnius.
