The prime ministers of Bulgaria, Serbia and Romania met in Sofia on Saturday.
The three Balkan leaders said they will not allow their countries to become a buffer zone for refugees if Germany, Austria and other countries close their borders.
Bulgarian Prime Minister Boyko Borissov says the intensive building of fences in Europe worried Bulgaria, Serbia and Romania, and the three countries are concerned about how far the refugee wave would reach.
Romanian Prime Minister Victor Ponta calls on all European countries to take responsibility and make joint moves across Europe to tackle the problem.
Serbian Prime Minister Aleksandar Vucic says a comprehensive solution is needed, but it could not be at the expense of Serbia, Bulgaria and Romania.
An unprecedented 670,000 people have flooded into Europe so far this year, mainly fleeing conflict in Syria, Iraq and Afghanistan.
Most are travelling through Turkey, Greece and the western Balkans, seeking new lives in Germany and other northern EU states.