Speaking in an interview with public broadcaster Polish Radio, Mariusz Błaszczak said that "fewer and fewer" migrants were attempting to illegally enter Poland from Belarus.
He added this was because 2,000 troops were helping border guards, and a solid fence was being erected along the frontier.
"We already have 60km of a 2.5m-high solid fence and 130km of military barbed-wire fence laid down along the border," he announced.
'Polish frontier is secure'
"The Polish frontier is secure," Błaszczak declared.
"The imposition of the state of emergency definitely minimised the danger of border provocations," he added.
Błaszczak told Polish Radio that the frontier fence was "a temporary measure" and that the government would consider further steps.
Poland declared a state of emergency in parts of two regions bordering Belarus on September 2.
Asked if the 30-day emergency measures would be extended, Błaszczak replied that "hopefully not, but that will depend on how the situation develops."
'Risk of provocations has diminished significantly'
"Let me reiterate very strongly that the risk of provocations has diminished significantly, thanks to the state of emergency along the border," Błaszczak told Polish Radio.
Polish President Andrzej Duda said last week his country was making every effort to safeguard the eastern frontier of the European Union from an influx of illegal migrants attempting to cross from Belarus.
Prime Minister Mateusz Morawiecki said the authorities in Minsk were responsible for the migrant surge.
"Not an hour passes without the Belarus authorities transferring migrants to the Polish border, from Iraq, Syria, Afghanistan, Lebanon, Egypt, Somalia--anywhere they can attract them," Morawiecki told a news conference last week.
Fellow EU members Lithuania, Latvia and Estonia have also accused Belarus' strongman leader Alexander Lukashenko of organising a wave of illegal migrants seeking to enter the bloc, as part of what officials have called a "hybrid war," Poland's PAP news agency reported.
The border situation is further complicated by joint Russian-Belarusian war games, Zapad-2021, being held near Poland, according to officials.