Over 68,000 people have crossed the Aegean Sea from Turkey to Greece this year, the UN refugee agency said Sunday, one day before German Chancellor Angela Merkel was due to travel to Ankara as part of her bid to curb migration to Europe.
An estimated 68,023 people travelled from the Turkish coast to Greek islands from the beginning of 2016 to February 6, according to the UN High Commissioner for Refugees.
At least 366 people lost their lives while attempting the perilous sea journey in a bid to reach Europe.
Merkel and Turkish Prime Minister Ahmet Davutoglu are to meet on Monday to discuss the implementation of a multilateral plan to crack down on smuggling networks and curb migration.
The European Union has pledged 3 billion euros (3.3 billion dollars) to Turkey to improve conditions for the millions of migrants living there.
However, that country faces a new wave of migration as violence in neighbouring Syria escalates, resulting in thousands of refugees from Aleppo gathering at the Turkish border in recent days.
Meanwhile, strict entry policies at Greece's border to Macedonia have resulted in crowds of over 7,000 migrants amassing at the Idomeni-Gevgelija railway crossing. Macedonian authorities are only allowing small groups of Syrian, Iraqi and Afghan migrants into the country.
Smugglers have been enjoying "good business" there, according to local officials, who said that traffickers tip off migrants to unmanned border points in exchange for cash.
In south-eastern Bulgaria, two migrants have frozen to death after being abandoned by traffickers.
The victims, a girl of about 14 and a woman aged about 30, were part of a group of 19 people that crossed over illegally from Turkey to the area of Malko Tarnovo, the Bulgarian Interior Ministry said.
The group was stranded after their guides left them behind in a forest in the mountains, in heavy snow and sub-zero temperatures, border police chief Antonio Angelov told the bTV channel.
The survivors, 10 of them children, were hospitalized with frostbite. Their claim of Iraqi and Afghan nationality was being checked, the ministry said.
Bulgaria, which is on the European Union's frontier with Turkey, lies just east of the main corridor that some 1 million migrants, many of them refugees from war zones, took to reach western Europe in 2015.