Presenting the conclusions of the meeting with officials from Serbia, Macedonia and Greece, Slovenian Interior Minister Vesna Györkös Žnidar told reporters that the meeting also agreed to improve coordination, including by exchanging data on refugee numbers and capacity occupation.

"Also worth considering is a single data basis that would enable better planning of [refugee] reception and further procedures in the countries further north along the route," the minister said.

While it was agreed that a slow-down would need to be applied to the migration flow, the minister said this was possible under the condition that accommodation capacities were increased.

"The joint conclusion of the meeting is that cooperation on the Western Balkan route is of vital importance because this is the only way to get to substantive management of migrations."

The commitments agreed today are to be settled on at an operational level at a meeting of police commissioners from the countries to follow shortly.

Györkös Žnidar said the meeting was "very successful" despite the absence of a representative from Croatia. "We need to make sure we have maximum control of the migrant flow, even if Croatia pushes us into a disproportionate position."

Vassilis Papadopoulos, the Greek secretary for migration policy, said it was necessary to reduce the inflow of refugees from Turkey, which is currently unmanageable.

He sees the need for better coordination as the main message of the meeting, but noted that there had been no talk about borders being closed. The closure of crossings is "not the future that Europe deserves," according to him.