Italy, France and Germany have signed a joint document calling for a review of EU asylum rules.
The declaration urges a "fair" distribution of migrants within the European Union.
Meanwhile hundreds of people have been stopped from travelling by train from Budapest for a second day and could be moved to special camps.
Hungarian government spokesman Dr Zoltan Kovacs has said they can't be sure of everyone's status: "There's no way you know who these people are because they come without papers.
"Establishing identity is basically impossible especially on the short-run it is taking months, or rather years, to establish identity."