Canada, the EU, UK and US imposed sanctions on Belarus after a Ryanair flight carrying an opposition journalist was forced into an emergency landing at Minsk airport.
The flight from Athens to Vilnius was diverted when Belarus claimed there was a bomb threat, which world powers suspect was a ruse to arrest the journalist.
The western powers issued a joint statement pledging their support to "the long-suppressed democratic aspirations of the people of Belarus".
"We stand together to impose costs on the regime for its blatant disregard of international commitments.
"We are united in calling for the regime to end its repressive practices against its own people. We are disappointed the regime has opted to walk away from its human rights obligations, adherence to democratic principles and engagement with the international community."
US Secretary of State Antony Blinken said the steps were taken because of the Ryanair incident and "the continuing repression in Belarus, including attacks on human rights, democratic processes and fundamental freedoms".
Britain said the sanctions would send a strong signal that it would not tolerate those who repress human rights coming to the UK or using British financial institutions.
“The UK and our partners have today sanctioned those responsible for the continued suppression of democracy and human rights in Belarus," Foreign Secretary Dominic Raab said.
“The Lukashenko regime endangered the lives of airline passengers and crew in a shameful ruse to snatch Roman Protasevich.
“We will hold the regime to account in co-ordination with our allies including through further banning travel, freezing assets and cutting off oil export revenue streams.”
Monday's joint statement called on the Alexander Lukashenko regime to co-operate fully with international investigations into the events of May 23 and the immediate release all political prisoners.
EU ambassadors this month agreed to ban Belarus airlines from flying over the bloc’s territory or landing at its airports.
Britain previously imposed sanctions on Mr Lukashenko, his son and senior figures in the Belarusian government under the UK's human rights sanctions regime in September 2020.