UN Secretary General Ban Ki-moon said more should have been done to tackle the "root causes" of the worst refugee and migrant crisis since World War II.
Slovenian authorities said they had refused to let in more than 1,000 migrants arriving from Croatia after a daily quota had been reached.
British Prime Minister David Cameron will launch a new strategy aimed at countering jihadist ideology and stopping young Britons travelling to Syria.
Turkish Prime Minister Ahmet Davutoglu praised a "better approach" from the European Union in sharing the burden of the refugee crisis.
US Secretary of State John Kerry rebuked those opposed to welcoming Syrian refugees, insisting that immigrants built and defined America as a nation.
The UN Security Council will vote on Friday on a draft resolution authorizing European military action against migrant smugglers in the high seas off Libya's coast.
Dubbed "the princess of migrants", a Nigerian baby born on the Italian ship that rescued her mother in the Mediterranean has become a symbol of hope for those braving the perilous crossing in search of a new life.
Traffic through the Channel Tunnel connecting Britain and France was suspended after around 100 migrants entered the French side of the tunnel complex, the company operating it said in a statement.
The huge influx of migrants into Europe is being used by some foreign leaders to weaken the European Union politically, EU president Donald Tusk said Friday in Poland.
Hungary's Prime Minister Viktor Orban warned at the United Nations that Europe will be "destabilized" if the mass flows of migrants and refugees continue unabated.
Kazakhstan is ready to accept refugees from Middle Eastern countries.
UN Secretary-General Ban Ki-moon welcomed the European Union's decision to inject $1 billion to help countries overwhelmed by Syrian refugees.
Australia's new Prime Minister Malcolm Turnbull admitted he had concerns about asylum seekers being held in Pacific island camps.
Slovakia's leftist Prime Minister Robert Fico said he would rather risk infringing EU rules than implement mandatory refugee quotas adopted by the bloc.
Four eastern EU states opposed to fixed migrant quotas across the bloc said they were "absolutely dedicated" to reaching an agreement with western partners on solving Europe's worst migrant crisis.
No European country can get out of taking in refugees who have the right to asylum, French President Francois Hollande said Sunday.
German Foreign Minister Frank-Walter Steinmeier said that EU members reluctant to accept migrant quotas may have to be outvoted and overruled in the 28-member bloc.
Hungary plans to build a fence to keep migrants out along part of its border with Romania in addition to the barrier being erected along the frontier with Serbia.
Hungary's populist prime minister called for a massive aid package to be given to countries around war-wracked Syria to help stem the flow of migrants to Europe.
EU ministers failed to reach agreement on a quota plan to share the burden of a flood of refugees.