Hungary's prime minister is calling on Germany to state they will not accept any more of the refugees travelling through Europe.
Viktor Orban has warned "millions" of people will descend on the continent if Berlin's open door policy continues - and criticised Austria for allowing migrants to "enter its territory without hindrance".
The right-wing leader also alleged that many of those who have worked their way through Turkey, Greece, Macedonia and Serbia to the European Union were not refugees in danger - but immigrants attracted by the prospect of a German lifestyle.
In an interview with Austrian television, Mr Orban claimed the crisis could also place an intolerable financial burden on EU nations, threatening the continent's "Christian welfare states".
Hungary's defence minister Csaba Hende resigned over the issue on Monday.
The country's police were accused of using pepper spray on refugees this afternoon as scuffles broke out on the southern border with Serbia .
In the coming days, Hungary is planning to "seal off" this border - effectively stopping any migrants or refugees from crossing over into the EU member state.
There are fears the 3.5m-high fence it is building could cause dangerous bottlenecks in Serbia, as thousands of people continue their desperate journeys along the Balkan corridor in search of a better life.
Mr Orban has defended the controversial project, and insisted Hungary is "protecting Europe according to European rules that say borders can be crossed only in certain areas in a controlled way and after registration".
He described his own country as the "black sheep" of the EU, and openly criticised the EU leadership's plans to introduce quotas and distribute migrants more evenly across the bloc's 28 member states.
Mark Wade, a volunteer who is helping police along Hungary's border with Serbia, said the mass migration is of "Biblical proportions" - claiming it is the biggest movement of people since World War Two.
"We're bussing people out - but the people are coming quicker than we can load them," he told Sky's Mark Stone.
The Hungarian government wants those arriving along the southern frontier to be sent to refugee camps close by, but they are already oversubscribed. One site is meant to hold 1,000 people, but is currently home to 1,300.
Further down the route, along the border Greece shares with Macedonia, scuffles have broken out between police and migrants, who were frustrated at how only small groups of people were being allowed to cross over every half an hour.
In the past 24 hours, more than 5,000 people have crossed over into Macedonia, according to Greek police.
More than 15,000 migrants arrived in Germany over the weekend, with moving footage emerging from Munich of families being reunited and refugees being cheered as they stepped off trains.
German Chancellor Angela Merkel told reporters: "We have a moving, in some parts breathtaking, weekend behind us."
Thousands more were expected to arrive in Bavaria, the country's largest state, on Monday.
Mr Orban's vocal criticism of Berlin comes days after Germany said it was putting "no limit" on the number of refugees it would give sanctuary - with officials estimating up to 800,000 migrants will have arrived by the end of the year.
Early on Monday morning, after hours of meetings held by Angela Merkel's government, Europe's wealthiest nation confirmed plans to spend €6bn next year on supporting the hundreds of thousands of new arrivals.
However, legal measures are being introduced that will make it easier to deport asylum seekers from countries considered as "secure states" - including Montenegro, Albania and Kosovo.
Those eligible to stay - often from Syria, Iraq, Afghanistan and Eritrea - will also receive more non-cash benefits in the future.
Germany's aid package is set to include improved housing and language classes for its refugees, along with bolstered federal police ranks.
Hours after Mr Orban's remarks, Mrs Merkel said: "Germany is a country willing to take people in, but refugees can be received in all countries of the EU in such a way that they can find refuge from civil war and from persecution."
Meanwhile, French President Francois Hollande said his country would welcome 24,000 refugees who have fled war.
David Cameron confirmed the UK Government planned to resettle up to 20,000 Syrian refugees from border camps in the next five years, after the Prime Minister dropped his opposition to taking in more people.
That followed the international outcry at images of three-year-old Aylan Kurdi, the Syrian boy whose lifeless body was found washed up on a Turkish beach after a failed crossing to the Greek islands.
Greece has now asked the EU for aid to prevent it being overwhelmed by refugees, claiming there are up to 18,000 migrants on Lesbos, an island which can cope with a maximum of 5,000.
Writing in The Times, Angelina Jolie called on the international community to find a diplomatic end to Syria's conflict, and warned "we cannot donate our way out of the crisis".
The UN special envoy also wrote: "We should be conscious of the distinction between economic migrants, who are trying to escape extreme poverty, and refugees who are fleeing an immediate threat to their lives.
"Syrians are fleeing barrel bombs, chemical weapons, rape and massacres."