Hungarian lawmakers will vote next week on whether to send troops to stem the influx, as more than 2,500 people crossed into the EU country from its southern frontier with Serbia, days before the completion of the razor-wire fence.
Syrians, Afghans and Pakistanis, including more than 500 children, are among those rushing to reach Hungary before the border is sealed.
"We left because we were scared – we had fear, bombs, war, killing, death," one Syrian man told Agence France-Presse as he headed for the Hungarian border.
"That's why we left Syria."
Floods and umbrellas
UN refugee chief Antonio Guterres and French Interior Minister Bernard Cazeneuve called for the urgent creation of more so-called "hotspots" – processing centers to sort refugees fleeing war from economic migrants who are simply in search of a better life.
As criticism mounted on the EU for its failure to reach a joint response to the crisis, Italy hit back at Germany and France over their claims that it is moving too slowly.
Merkel, at talks on Monday, August 24, with French President Francois Hollande, warned that it would be intolerable if registration centers in Italy and Greece were not operational by the end of the year.
"Asking Greece and Italy to do their duty on immigration is like asking a country hit by floods to step up the production of umbrellas," Foreign Minister Paolo Gentiloni told the Corriere della Sera newspaper.
Leaders from the western Balkans – the region that has become one of the main routes into the EU – will attend a summit in Vienna on Thursday, August 27, joined by Merkel, in a bid to work out a coherent approach to the crisis. – Coralie Febvre with Csaba Ranks in Roeszke, Hungary, AFP / Rappler.com