The International Organization for Migration says more than 1 million immigrants have entered into Europe over the last year.

With just days left in 2015, the Geneva-based intergovernmental organization says the million mark was crossed Monday - marking more than a four-fold increase from last year.

The IOM says that more than 800,000 have crossed into Greece from Turkey which includes more than 455,000 from Syria and 186,000 from Afghanistan.

Around 3,700 people died trying to cross the Mediterranean.

The BBC says 1 million migrants is a fourfold increase from last years numbers.

Most of the migrants who died - 2,889 - were making the sea crossing between north Africa and Italy, while more than 700 died in the Aegean crossing to Greece from Turkey.

IOM director William Lacy Swing said "We must also act. Migration must be legal, safe and secure for all - both for the migrants themselves and the countries that will become their new home."

A joint IOM and UNHCR statement said "a more co-ordinated European response is beginning to take shape".