Migrants wait to board busses in Nickelsdorf, Austria September 14, 2015. [Photo/Agencies]

VIENNA - Austria is following Germany in introducing tougher border controls, and it is deploying the army to assist in dealing with an influx of migrants, Vice Chancellor Reinhold Mitterlehner told a news conference with Chancellor Werner Faymann.

"If Germany carries out border controls, Austria must put strengthened border controls in place," Mitterlehner said. "We are doing that now."

Faymann said he did not know of a single case in which Germany had sent a migrant back to Austria since Berlin announced on Sunday that it was reintroducing border controls.