The EU has decided to ban Belarusian airlines from European skies after a flight was diverted to Minsk on Sunday and a dissident journalist arrested.
At a meeting in Brussels, the leaders of the 27 member states also told EU airlines not to fly over Belarus, and promised further economic sanctions.
Roman Protasevich, 26, was on a flight from Greece to Lithuania which was rerouted over a supposed bomb threat.
Western countries accused Belarus of hijacking the Ryanair plane.
Belarus authorities on Monday released video of Mr Protasevich that appears to have been recorded under duress since his detention at Minsk airport.
In the clip, the journalist said he was in good health and seemingly confessed to crimes he had been charged with by the Belarusian state.
But activists, including the country's main opposition leader, criticised the video and suggested Mr Protasevich was under pressure to admit wrongdoing.
US President Joe Biden described the actions of the Belarusian authorities as "outrageous", saying they were "shameful assaults on both political dissent and the freedom of the press".