Ankara issued a new Navtex advisory for its Oruc Reis research boat late on 11 October. The advisory is set to last until Thursday, and Turkish officials have said that the seismic surveys have already got underway.
"It came as a surprise – a very bad surprise. This back and forth of de-escalation and escalation is difficult to understand and leads to a dead end," Maas told the newspaper.
Tensions between Ankara and Athens flared throughout the summer after Turkish research vessels conducted several seismic surveys in the eastern Mediterranean Sea. The European Union has strongly criticized Turkey's actions, although Brussels has yet to slap sanctions on Ankara.
Maas said that a decision on whether to levy punitive measures against Turkey might be taken in December.
"They [sanctions] are part of our diplomatic toolbox, but they should be used with precaution. Are we already at this point regarding Turkey? Might we get there? This should depend on Ankara. We have set out a clear and measured way forward until the Council in December. It is up to Turkey to come on board. And in December we’ll have to decide," the German foreign minister said.
Turkey issued the latest Navtex advisory just a handful of days after Greek Foreign Minister Nikos Dendias met with his Turkish counterpart Mevlut Cavusoglu on the sidelines of a forum in Slovakia's capital, Bratislava.
Maas said that meetings such as these were a positive starting point from which to maintain dialogue.
The Greek government has slammed Turkey for conducting the seismic exploration surveys in waters that Greece claims to be part of its exclusive economic zone.
NATO is also playing a leading role in trying to defuse the tensions, and a so-called de-confliction mechanism has been established to reduce the risk of accidents taking place in the region.
