The tension created in the Aegean this week by a Turkish Navtex that reserved areas within the Greek continental shelf for seismic surveys is “heading towards de-escalation” but Greek authorities remain vigilant, the prime minister’s national security advisor said on Friday.

Speaking to Greek broadcaster Skai, Alexis Diakopoulos ruled out the possibility of an incident in the Aegean, saying Greece has an effective deterring power and that “it is not easy to do this bullying and succeed.”

He said the de-escalation is the result both of the determination shown by Greece and the political pressure exerted on Turkey by other countries, such as Germany.

Diakopoulos said German Chancellor Angela Merkel “made the most dynamic intervention,” and welcomed the decisive meeting between Erdogan’s top security adviser Ibrahim Kalin and his Greek counterpart Eleni Sourani in Berlin.