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 said on 5 November, 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.

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

"And if that is the case, we are looking into another 600,000 refugees and migrants arriving in Europe between November this year and February next year. We have seen the number of tragedies in the Aegean increasing in recent months because of the deterioration of the weather conditions. So more people are going to die if we don't act now."

More than 3,400 migrants have died trying to reach Europe this year by sea. On 5 November, one child drowned and another was missing off the Greek island of Kos after a boat carrying migrants sank, the coastguard said.

The 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 $96.15m (£63m) 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 World War Two to $172.7m.

Spindler criticised the failure of the European Union's member states to agree on 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. We think that this is not right, but since at the moment there is no appropriate response, UNHCR and other humanitarian organisations are having to fill that gap."

A UNHCR statement said that the fresh funds would be used to upgrade shelter and reception facilities for winter conditions, and to supply family tents and housing units equipped with heating. As well, sanitation and water supply systems would be improved to provide hot showers, toilets, and laundry facilities, while winter clothing, thermal blankets, boots, socks, raincoats and head lamps would be distributed. It urged donor states to allocate funds as flexibly as possible because the routes taken by the refugees were continually changing.