"By this time, 180,000 migrants have already arrived. This figure may reach 400,000 or even 500,000 by the end of the year, if Hungary does not strengthen its borders," Peter Szijjarto was quoted as saying by the HGV.hu news portal Saturday.
The EU member states, including Hungary, have been struggling with an unprecedented influx of refugees as tens of thousands try to enter the bloc, fleeing violence in their home countries.
A new Hungarian law on border protection, which will come into force on September 15, introduces prison terms for illegally crossing the country's borders.
On September 22, the state’s parliament is also due to mull the dispatch of the army to the border to contain the EU-bound refugees. At present, only police units are charged with border protection, according to the Hungarian government.