“We do not know what will happen in the coming days, and that is why we have introduced a state of emergency to guard the border," Rau said during the Economic Forum in the Polish resort town of Karpacz.
"We remain determined to protect our border with Belarus, which is also the border of the European Union,” he added.
Last week, Poland declared a state of emergency in parts of two regions along its border with Belarus.
The annual Economic Forum in Karpacz, billed as the largest conference of its kind in Central and Eastern Europe, runs until Thursday.
The conference, which is sometimes referred to as the “Polish Davos,” includes more than 350 panel discussions and lectures as well as workshops and other events focusing on some of the most pressing problems in Central and Eastern Europe.
Wednesday's agenda includes debates on climate neutrality, tax policies and the impact of the COVID-19 pandemic on young people.