The UN's refugee agency does not expect the flow of about 8,000 migrants and refugees per day into Europe to abate.
UNHCR regional refugee coordinator Amin Awad warned that it could be "the tip of the iceberg".
Hungary is to seek support for its efforts to try to block the number of migrants on its southern border with Croatia, similar to the measures implemented on its border with Serbia, Prime Minister Viktor Orban said.
"This is the big question of the next few days and weeks, I am trying to seek supporters for this," Mr Orban told a news conference in Vienna, after meeting Austrian Chancellor Werner Faymann.
He said Hungary would make a decision about sealing off its border with Croatia only after consultations to gather support for the move.
"The way I see it now is that, even if not whole-heartedly, Austria acknowledges that Hungary, if it wants to uphold international agreements, should implement actual border controls along the Croatian-Hungarian border," Mr Orban said.
Meanwhile, the UN's deputy humanitarian coordinator in Iraq said 10 million people in Iraq were expected to need humanitarian support by the end of the year, where 3.2 million are already displaced.
Dominik Bartsch said the United Nations was planning for the displacement of 500,000 people from the Iraqi city of Mosul if Iraqi forces launch an attempt to recapture the city from the so-called Islamic State group.
Finnish government condemns racist attack on refugees
Demonstrators threw stones and launched fireworks at a bus carrying asylum seekers arriving at a reception centre in Lahti in southern Finland last night, according to Finnish media.
Between 30 and 40 demonstrators, one in a white robe like those worn by the white supremacist Ku Klux Klan in the United States, waved the Finnish flag and shouted abuse at the bus.
Some demonstrators also hurled stones and let off fireworks at the vehicle carrying 40 asylum seekers, including several young children, Finnish television YLE said.
Meanwhile, a petrol bomb was thrown at another reception centre in Kouvola, also in southern Finland, police said.
No one was known to be hurt in the incidents.
"The Finnish government strongly condemns last night's racist protests against asylum seekers who had entered the country," the government said in a statement.
"Violence or the threat of violence is always to be condemned."
Prime Minister Juha Sipila this month offered to take in refugees at his home, a move that attracted international attention but also criticism in Finland.
"Sipila's noble-minded gesture was like a Christmas gift for human traffickers and refugees. The news about open doors in Finland have sent many young men on a journey towards the promised land," Mika Niikko, a deputy from anti-immigrant party The Finns, said last week in a statement.
So far this year more than 13,000 asylum seekers, most of them from Iraq, have come to Finland, compared to just 3,600 in the whole of last year.
In recent days, about 500 refugees per day have crossed the Finnish land border in Tornio, near the Arctic Circle, after along journey through Sweden.
The Finnish government has launched random border checks and identity checks around the country amid the influx.
Finland was the only European Union state to abstain from this week's vote about relocating asylum seekers across the member countries.
It accepted its 2% share of 120,000 asylum seekers in question but said it was opposed to a mandatory quota system.
