Alexander Lukashenko has been sworn in for a fourth term as Belarus's president in the capital Minsk, after his election last month.
The inauguration takes place as European officials consider imposing strict sanctions against Belarus for a crackdown against the opposition.
EU officials boycotted the inauguration ceremonies.
The European parliament has passed a resolution calling for new elections in Belarus.
President Lukashenko was sworn in for his five-year term in Minsk's central Palace of the Republic.
On election day on 19 December thousands of demonstrators gathered to protest against Mr Lukashenko's re-election in the square just outside the concert hall. They said the vote was rigged.
After some tried to storm the main government building police broke up the crowds, beating protesters and arresting hundreds.
Many, including the main opposition candidates, still remain in jail, and more than 30 people are facing lengthy prison terms for causing mass disturbances.
The international reaction to the beatings and arrests has been sharp.
EU ministers will meet on 31 January to decide whether to impose severe sanctions, including a visa ban and asset freeze for top Belarus officials, including Mr Lukashenko.
Poland's government has already enacted a unilateral travel ban against the Belarussian authorities, and has encouraged other European countries to follow suit.
Belarus, for its part, accuses Polish and German officials of trying to stage a coup d'etat on election day, an accusation that Warsaw and Berlin deny.