Polish Interior Minister Mariusz Kaminski was quoted as saying by news agency PAP on Thursday that the government would announce an extension until Nov. 2, following a similar order announced by the Czech government on Wednesday evening.
The two countries, along with Austria, tightened their borders with Slovakia on Oct. 4 to guard against smugglers and a rise of illegal migrants.
"There are good results, there are clear effects," Kaminski said.
Slovakia is a transit country for migrants mostly from the Middle East and Afghanistan who are seeking to reach Germany after crossing into the European Union through Hungary from Serbia, which is not in the EU.
On Wednesday, Slovakia extended its own border controls with Hungary until Nov. 3. The number of migrants entering Slovakia has risen eleven-fold to nearly 40,000 this year, government data shows.
Last month Germany also introduced checks on its borders.
Poland, Slovakia, the Czech Republic, Hungary, Austria and Germany are all part of the EU's Schengen open-border zone.
The issue of illegal migration has featured prominently in campaigning for elections in central Europe.
Slovakia's SMER-SSD party won a Sept. 30 election on pledges to step up border patrols, while Poland's ruling Law and Justice (PiS) party has branded the opposition soft on migration as it seeks a new term in an Oct. 15 poll.
(Reporting by Anna Wlodarczak-Semczuk in Warsaw and Jason Hovet in Prague; Editing by Deborah Kyvrikosaios and Gareth Jones)
