KASTANIES, Greece — Clashes between Greek riot police and migrants attempting to cross the border from Turkey erupted anew Friday as European Union foreign ministers took aim at what they called “Turkey’s use of migratory pressure for political purposes.” Greek riot police used tear gas and a water cannon to drive back people trying to cross the land border from Turkey in the morning. Turkish police fired volleys of tear gas back toward Greece in an ongoing standoff between Ankara and the EU over who should care for migrants and refugees. Similar clashes erupted later Friday, and fires were seen burning on the Turkish side of the border that Greek officials said were lit by migrants. Thousands of refugees and other migrants have been trying to get into Greece through the country’s eastern land and sea borders in the past week after Turkey declared its previously guarded borders with Europe were open. Following through after months of threats, Turkish President Recep Tayyip Erdogan said last week his country, which already houses more than 3.5 million Syrian refugees, would no longer be Europe’s gatekeeper. He has demanded Europe shoulder more of the burden of caring for refugees. But the EU insists it is abiding by a 2016 deal in which it disbursed billions of euros in refugee aid in return for Turkey keeping refugees on its soil. Erdogan on Friday held a telephone call with German Chancellor Angela Merkel, during which he told her that the Turkey-EU migration arrangements are no longer working and need to be revised, according to a statement from Erdogan’s office. Erdogan’s border decision has alarmed EU countries, which are still seeing political fallout from mass migration five years ago. EU foreign ministers met in Zagreb, Croatia, on Friday to...