Turkish President Recep Tayyip Erdogan has accused Greek Prime Minister Kyriakos Mitsotakis of "lying" about the refugee crisis."It is truly ingratitude to say that the refugee crisis is caused by Turkey," Erdogan said at a joint press conference with visiting Hungarian Prime Minister Viktor Orban.It is Greece that pushes refugees to their deaths in the Mediterranean and Aegean Seas, he added.Mitsotakis said on Tuesday that Greece intercepted boats coming from Turkey but denied claims that his government pushed back the refugees, Xinhua news agency reported."So rather than blaming Greece, you should put it on those who have been instrumentalizing migration systematically," he added.Thousands of refugees are gathering on the Belarusian side of the border in an attempt to enter Poland and then Germany to seek asylum.Turkish Foreign Minister Mevlut Cavusoglu on Wednesday discussed the issue with his Polish counterpart Zbigniew Rau on the phone.