Poland plans to start building a permanent barrier on the EU's external border with Belarus on Tuesday.
"The work will start with drilling holes for the piles and setting them in concrete," the Border Guard spokeswoman told the PAP news agency on Monday.
For months, thousands of migrants have been trying to reach the EU, usually via Belarus to Poland or the Baltic states.
The EU has accused Belarusian ruler Alexander Lukashenko of deliberately flying people from war-torn countries to Minsk, before encouraging them to mass at the EU border in an effort to destabilize the bloc in retaliation for the economic sanctions it has imposed on his government.
Poland's border with Belarus is 418 kilometres long, with 186 kilometres running over land. At end of August, soldiers already erected a temporary fence about 2.5 metres high on these sections using barbed-wire.
It is now to be replaced by a permanent 5.5-metre-high barrier, equipped with motion detectors and cameras. A budget of around 366 million euros (413.98 million dollars) has been earmarked for the project.
