The march marks Freedom Day – known in Belarusian as Dzień Voli – commemorating the declaration of the Belarusian People's Republic on 25 March 1918.
Warsaw's Palace of Culture and Science was lit in the white-red-white colours of the Belarusian democratic movement on Wednesday – three days before Saturday's march.
The date is not officially recognised by Alexander Lukashenko's government, which instead marks independence on 3 July, the anniversary of the Soviet liberation of Minsk in 1944.
Tsikhanouskaya noted that Lukashenko visited North Korea on 25 March, describing the trip as a "symbolic gesture" showing that while Belarusians celebrate freedom, their leader was marking what she called "a day of slavery".
"For Belarusians, this day has become a symbol of the pursuit of freedom and resilience – because for the past 30 years, Belarusians have taken to the streets on this day," she noted.
The march, starting at 4 p.m. local time at Warsaw's Plac Trzech Krzyży and ending at Castle Square, will be followed by a concert and speeches, including from opposition figure Pavel Latushka.
Speakers will address the issue of political prisoners – currently numbering 908, according to the Viasna Human Rights Centre.
Tsikhanouskaya warned that participation still carries risks for Belarusians, saying plainclothes KGB agents photograph marchers' faces, with consequences including property confiscation.
She urged both Poles and Ukrainians to join the event.
(ał)
Source: PAP