It was due to take place in three days time.
But a delay has been announced in the investiture of the newly re-elected leader of Belarus, Alexander Lukashenko.
No reason has been given for the postponement.
It comes amid opposition calls for fresh rallies to protest at the ballot that kept him in power.
The poll has been branded fraudulent by the United States, the European Union and international observers. But a group of pro-presidential activists who reject that view gathered outside the Polish Embassy in Minsk to protest at what they describe as Warsaw's interference in their country's internal affairs.
The two neighbours have particularly difficult relations. A former Polish ambassador to Belarus is among over 150 people to have been jailed in the wake of opposition protests.
Also in custody is one of the defeated election candidates. Arrested at the weekend during a rally in the capital, Alexander Kozulin could face up to six years behind bars on hooliganism charges.
There were ugly scenes during Saturday's demonstration as security forces moved in.
Police said they only used force after the event turned violent.