Thousands of migrants remain stranded on Greece's northern border and near Athens as non-EU Macedonia refuses to allow passage to Afghans.
Reports say about 5,000 people were stuck at Idomeni or on buses near the Macedonian border on February 22, while another 4,000 arrived at Piraeus port.
Macedonia says only Syrians and Iraqis will be let in, claiming Afghans were not being allowed passage by Serbia.
Belgrade has not provided a clear answer to whether Afghans were banned from entering.
Until now, Afghans have been allowed to pass through alongside Syrians and Iraqis.
Austria last week introduced a daily limit of 80 asylum claims, triggering fears of a domino effect along the Balkan route.
Nearly 100,000 migrants and refugees have traveled to Greek islands from nearby Turkey so far this year.
