Austria will erect a 3.7-kilometre (2.3-mile) metal fence along its border with Slovenia to better manage the influx of migrants, with barbed wire stored nearby ready to install if needed, Vienna said Friday.

"We are talking here about an ordered inflow and not a barrier," Chancellor Werner Faymann's chief of staff Josef Ostermayer told reporters, two days after Slovenia began similar measures on its frontier with Croatia.

The barbed wire will be stored in containers ready to be rolled out if the situation escalates, Ostermayer told a news conference. Interior Minister Johanna Mikl-Leitner said the fence will be 2.2 metres high.

Austria has become a major transit route for hundreds of thousands of migrants and refugees heading for northern Europe this year.

Most travel onwards to northern Europe but Austria still expects a record 95,000 asylum claims this year, making it one of the highest recipients on a per capita basis.

Faymann's government has also come under pressure to do more to stem the flow because of growing support for the far-right Freedom Party, which is leading opinion polls.