Refugees and migrants are likely to keep coming to Europe at a rate of up to 5,000 per day via Turkey this winter, the United Nations has said, meaning that more than a million people will have fled to the continent this year.

About 760,000 people have already crossed the Mediterranean in 2015, mainly to Greece and Italy, after fleeing wars in Syria, Afghanistan and Iraq, as well as conflicts in Africa.

William Spindler, a spokesman for the UN High Commissioner for Refugees (UNHCR), said: "We need to prepare for the possibility of up to 5,000 to continue arriving every day from now until February next year.

"If that is the case, we are looking at another 600,000 refugees and migrants arriving in Europe between November this year and February next year."

"It will put the figure over a million for this year."

In 2014, 216,000 people arrived in Europe by sea seeking asylum, a number matched by those arriving this October alone.

Mr Spindler added: "If we don't take the necessary action, we fear more people will die because of the harsh conditions of winter in Europe. We have already seen a number of shipwrecks off Greece and we are afraid people might also die from exposure on the way between Greece and central and northern Europe."

More than 3,400 migrants have died trying to reach Europe this year by sea. On Thursday, one child drowned and another was missing off the Greek island of Kos after a boat carrying migrants sank, the coastguard said.

UNHCR is providing aid at more than 40 sites in Greece, including 20 islands and islets, among them the main destination, Lesbos.

It is seeking an additional £60million to support Croatia, Greece, Serbia, Slovenia and Macedonia, bringing the total amount that it is trying to raise for Europe's biggest refugee crisis since the Second World War Two to £120m.

Mr Spindler criticised the failure of the European Union's member states to agree a comprehensive response.

"Europe has the means to deal with this situation but is not dealing with it," he said. "And now, aid agencies such as UNHCR and others are having to come to Europe to respond."

The fresh funds will be used to upgrade shelter and reception facilities for winter conditions, and to supply family tents and housing units equipped with heating.

Sanitation and water supply systems will be improved to provide hot showers, toilets, and laundry facilities. Transport may be provided if national authorities are unable to do so, to avoid people having to walk in the cold to reach registration points.

Winter clothing, thermal blankets, boots, socks, raincoats and head lamps will be distributed, a UNHCR statement said.

It urged donor states to allocate funds "as flexibly as possible" as the routes taken by the refugees were continually changing.