By Sonia Bakaric and Eric Randolph
Europe is becoming increasingly divided over its refugee crisis as record numbers of migrants stream through the Balkans into Hungary, forcing Austria to suspend cross-border train services.
Germany has warned that an EU plan to distribute 160,000 new arrivals among member states was a mere "drop in the ocean", but it faces stiff opposition from eastern members who say they will not accept binding quotas from Brussels.
Hungarian police on Thursday (local time) said 3321 people had entered in just 24 hours, hurrying to cross before harsh new anti-migrant laws take effect, an imposing new fence is completed, and the weather worsens.
Across the border in Serbia, state television reported that a record 5000 people had arrived at the frontier.
Further south, on Macedonia's border with Greece, AFP journalists saw some 50 buses transporting about 2500 migrants and three trains packed with 3000 people departing from the town of Gevgelija.
The UN's refugee agency on Tuesday warned that at least 42,000 migrants were expected to enter Hungary by next week.
Many have endured treacherous sea journeys across the Mediterranean - most fleeing war and poverty in Syria, Afghanistan or Pakistan and hoping to reach Germany.
EU interior ministers will meet on Monday to discuss a plan unveiled by European Commission chief Jean-Claude Juncker to share out 160,000 refugees across the bloc and ease the burden on frontline states.
Germany, which has already welcomed 450,000 migrants this year, wants the 28-nation group to go further, calling for no limits to the quotas.
But binding quotas are already facing fierce resistance from eastern EU members and Brussels may have to call a special summit to get them approved.
"It is inappropriate to talk about mandatory quotas, calculated on an extremely bureaucratic basis, almost like an accountancy exercise I might say, without consulting member states," Romania President Klaus Iohannis said.
His views echoed those of Slovakian Prime Minister Robert Fico, who said he did not "want to wake up one day and have 50,000 people here about whom we know nothing".
German Foreign Minister Frank-Walter Steinmeier will try to win over eastern European counterparts at a meeting in Prague on Friday.