Germany’s foreign Minister slammed Turkey’s gas exploration plans in the eastern Mediterranean Sea today, reiterating what other European states have said as the dispute continues.

Speaking in Athens, Heiko Maas said that relations between Europe and Turkey can only improve if Turkey ceases the drilling.

“Regarding Turkey’s drilling in the eastern Mediterranean, we have a very clear position — international law must be respected so progress in EU-Turkey relations is only possible if Ankara stops provocations in the eastern Mediterranean,” said Maas, according to Reuters.

Turkey plans to drill for gas in the eastern Mediterranean, per an agreement with Libya’s UN-backed Government of National Accord. Greece and Cyprus consider the area their territorial waters.

“The illegal and provocative behavior of Turkey has a serious backlash not only to peace and stabiity in the Eastern Mediterranean but to the cohesion of NATO and to its relations with the European Union,” said Dendias, as reported by Reuters.

Maas’ Greek counterpart unsurprisingly struck a similar tone in his comments on Tuesday, saying the drilling threatens the NATO alliance that Turkey, much of Europe and the United States are a part of. Greek Foreign Minister Nikos Dendias met Maas in Athens and the two discussed the drilling among other issues.

Many European countries share Germany’s concerns with Turkey’s gas exploration. The European Union also considers the area in question to be Greek and Cypriot waters. France in particular has been vocal in its opposition to the drilling. The Franco-Turkish tensions also relate to Libya and France left a NATO mission in the Mediterranean last month over a spat with Turkey.

The Mediterranean Sea is not the only site of Turkey’s recent energy projects. A Turkish ship began drilling in the Black Sea this month. The country’s Minister of Energy and Natural Resources Fatih Donmez called the project a bid for “Turkey’s energy independence,”.