The European Union has announced that it is preparing a list of sanctions against Turkey that could be on the agenda at the bloc’s next summit on September 24, following repeated Turkish aggression and incursion in Greek territorial waters.

The announcement came after Greek Foreign Minister Nikos Dendias, arriving at an informal meeting of the EU’s Foreign Ministers, called sanctions absolutely necessary in order to stop Turkey’s aggression against Greece.

The measures, meant to limit Turkey’s ability to explore for natural gas in contested waters, could include individuals, ships or the use of European ports, Josep Borrell said. The EU would focus on everything related to “activities we consider illegal”, he added.

He spoke in Berlin where EU foreign ministers met to discuss support for Greece after Athens ratified a pact on its maritime boundaries to counter Turkey’s claims to energy resources in the region amid Greek and Turkish military exercises.

Borrell, who chaired the meeting, said the bloc was ready to sanction Turkish vessels, block their access to EU ports and cut off supplies. The EU could also impose sanctions on the Turkish economy.

“We can go to measures related to sectoral activities … where the Turkish economy is related to the European economy,” Borrell told a news conference, referring to possible sanctions.

Borrell insisted that “the most pressing issue is that of the drilling and the presence of Turkish ships in the territorial waters of Greece and Cyprus- something that is dangerous.”

Greek Foreign Minister Nikos Dendias hailed the decision.

“I think the Greek side got what it could get: An agreement on sanctions, if Turkey does not de-escalate and does not return to the dialogue table,” Dendias said after the meeting of EU foreign minister in Berlin.