Austria has held a high-profile training exercise to show how it could deal with an influx of refugees along its frontier with Slovenia.
Hundreds of police in heavy armour, backed by soldiers and Black Hawk helicopters flying overhead, performed a dry run for the media near Spielfeld, 110 miles south of Vienna.
The town was a major crossing point for migrants in late 2015, but has hardly seen any arrivals recently.
The "migrants" were played by 200 Austrian police cadets, who chanted and rattled the metal fence, demanding to be let in.
Austria's top security official said the exercise was necessary and lawful, dismissing concerns at home and abroad.
"A state which, if things come to a head, can't protect its borders effectively loses its credibility," interior minister Herbert Kickl told reporters.
"I'm strongly determined that events like those in 2015 must never happen again."
Kickl said he wanted to prevent people from abusing the right to asylum.
"This has nothing to do with inhumanity, this isn't unlawful, this isn't indecent," he said.
"This is what the law demands from us. It is what the people expect from us."
Kickl's far-right Freedom Party has pushed for a hard line against migrants for years and saw a surge in support following the 2015 migrant crisis, when thousands of people fleeing war and hardship at home poured through Europe's open borders daily.
It triggered a humanitarian and political crisis that has left deep divisions on the continent.
German Chancellor Angela Merkel is under pressure from conservative allies in Bavaria to turn migrants who come through other European countries back at the border.
Merkel, whose decision to allow migrants stuck in Austria and Hungary to come to Germany was initially welcomed by voters, has warned that unilaterally closing borders could prompt the triggering of a string of national measures by individual countries that would further divide Europe.
Speaking in Berlin, Merkel said most EU countries were more concerned about preventing migrants from illegally entering Europe in the first place.
Neighboring Slovenia protested against the Austrian exercise, saying its own forces were already doing enough to protect the external borders of the Schengen travel zone within which Europeans can travel freely without passports.
"I even see it (the exercise) as somewhat provocative," Slovenian Prime Minister Miro Cerar said on Tuesday, according to the official STA news agency.
Cerar said the number of migrants entering Austria from Slovenia has not increased and described his country as an "exemplary" protector of the Schengen border.