Migrants and refugees sleep on the ground next to a graffiti on the wall reading 'solidarity with the immigrant', in Victoria Square, where hundreds of migrants and refugees found temporary refuge, in central Athens on September 26, 2015. Russian President Vladimir Putin and Greek Prime Minister Alexis Tsipras spoke by phone on September 25, 2015, about strengthening bilateral ties and the growing migrant crisis, the premier's office said. AFP PHOTO / ANGELOS TZORTZINIS        (Photo credit should read ANGELOS TZORTZINIS/AFP/Getty Images)