The unrest in Belarus poses the biggest challenge yet to President Alexander Lukashenko, accused by protesters of rigging Sunday's presidential election to win a sixth term.
Poland's plan, which would also provide scholarships for academics and funding for the independent media, will initially cost around PLN 50 million (USD 13m, EUR 11m), Prime Minister Mateusz Morawiecki told the Polish parliament.
"Empathy is not enough - we need to take concrete action," he said.
Soon after Morawiecki's speech, several hundred people took to the streets of Warsaw in solidarity with those protesting in Belarus.
They carried Belarusian and EU flags as well as banners saying "The Belarusian nation needs support!" and "We don't want war, we want freedom."
In Brussels, momentum was growing in favour of sanctions in emergency discussions among EU foreign ministers on Friday.
An EU diplomat said the gathering decided to instruct their foreign policy unit to prepare a list of individuals to be blacklisted, marking a first step towards new sanctions.
Poland's support programme comes after it demanded the European Union host a special summit on Belarus.
Morawiecki called for the EU to take further action. "In this moment, you can't don the mask of neutrality or indifference. If we don't take steps as a united Europe now, then we will let it be known to all of our neighbours that when they are threatened, one can only count on oneself," he said.
Because Poland belongs to the EU's Schengen area, anyone who enters legally from Belarus can travel freely within the other 25 Schengen countries.
Morawiecki reiterated his government's demand that Belarus rerun its elections with foreign observers present, echoing his Czech counterpart, Prime Minister Andrej Babis.
Poland shares a close history with Belarus, home to between 300,000 and 1.2 million people of Polish origin.
Source: Reuters. By Kacper Pempel and Joanna Plucinska