US President Joe Biden slammed Belarus on Monday for the "outrageous" act of forcing a flight from Greece to Lithuania to land in Minsk where a dissident journalist onboard was arrested.

"This outrageous incident and the video Mr. Pratasevich appears to have made under duress are shameful assaults on both political dissent and the freedom of the press," Biden said, using an alternative spelling of the activist's name, after Belarusian TV broadcast video of Roman Protasevich "confessing" to charges of organizing mass unrest.

"I welcome the news that the European Union has called for targeted economic sanctions and other measures, and have asked my team to develop appropriate options to hold accountable those responsible," Biden added in his statement.

Belarus's strongman leader Alexander Lukashenko sparked international outrage by dispatching a fighter jet Sunday to intercept the Ryanair flight from Athens to Vilnius carrying Protasevich, 26, and his girlfriend Sofia Sapega.

EU leaders agreed Monday to cut air links with Belarus, and the bloc said it would adopt further "targeted economic sanctions" against Belarusian authorities to add to the 88 regime figures and seven companies already on a blacklist over a crackdown on opposition.

The TV footage showed Protasevich -- who could face 15 years in jail -- with dark markings on his forehead, saying he was being treated "according to the law."

"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 Lukashenka regime," Biden said.

The White House added that National Security Advisor Jake Sullivan had spoken to exiled opposition leader Svetlana Tikhanovskaya, to convey "the United States' strong support for the demands of the Belarusian people for democracy, human rights, and fundamental freedoms."