By Dasha Afanasieva and Lefteris Karagiannopoulos ANKARA/ATHENS (Reuters) - EU Council President Donald Tusk told illegal economic migrants on Thursday not to risk their lives or money to make a perilous trip to Europe "for nothing" but said unilateral actions by European Union states to deal with the crisis must stop. The ultimate aim was to eliminate the illegal sea transit of migrants from Turkey to Greece, Tusk said after meeting Turkish Prime Minister Ahmet Davutoglu in Ankara and Greek Prime Minister Alexis Tsipras in Athens, although he said no specific numbers had been agreed with the Turks.