Austria has deployed armoured vehicles close to its border with Italy and will send up to 750 soldiers to block any migrants trying to head north, the government announced.

The move reflects deep concern in Vienna and elsewhere in Europe over the huge number of asylum seekers who continue to cross the Mediterranean from Libya – so far this year more than 85,000 have been rescued and brought to Italy.

But it prompted a rebuke from Rome, with the Italian foreign ministry summoning Austria’s ambassador to explain the beefing up of border security. Italy has warned in the past that such measures would contravene EU rules on free movement.

Austria said it would ramp up border controls at the Brenner Pass, a key trade and transport route through the Alps that connects the two countries. "We are ready to protect our Brenner border if necessary,” said Sebastian Kurz, the Austrian foreign minister.

The 750 soldiers could be rushed to the border within 72 hours if there was a migration emergency, officials said. "I expect border controls will be introduced very soon," Peter Doskozil, the defence minister, told the newspaper Kronen Zeitung.