The EU is bracing itself for up to three million more refugees and migrants arriving in the 28-nation bloc by the end of 2016.

So far this year, more than 700,000 people fleeing war and looking for safety or a better life have entered the territory, with chaotic consequences for governments throughout the EU who have not yet worked out a strategy for coping with the huge numbers.

Now, forecasters say, based on current levels and imagining similar flows of people, the number of those arriving is unlikely to slow before 2017.

EU autumn economic forecasts released on Thursday say that, based on current migrant entries and a "technical assumption" about future flows, arrival rates are unlikely to slow before 2017.

The European Commission points out that even though the current crisis has been an additional burden on government spending, there could be a benefit for EU economies within a few years.

The United Nations, meanwhile, is warning that up to 5,000 refugees and migrants are expected to arrive daily to the EU from Turkey this winter.

It has launched an appeal to raise €88m to help Greece and the surrounding Balkan countries fund the influx.

"Harsh weather conditions in the region are likely to exacerbate the suffering of the thousands of refugees and migrants landing in Greece and travelling through the Balkans, and may result in further loss of life if adequate measures are not taken urgently," the UNHCR said in a statement.

Greece, one of the countries most affected by the crisis, has begun a programme to disperse some of the people who travelled from Turkey in barely seaworthy boats to look for a different life.