Albania has officially launched a complaint with Greece concerning the land and sea borders dividing the two countries.
Hydrocarbon exploration in the Ionian Sea by Greece as well as onshore explorations for gas reserves in Epirus led the Albanian government to raise concerns over territorial violations last week, a number of media sources reported.
Epirus, which was once home to a thriving community of Cham Albanians before they were expelled by the Greeks during World War II after being accused of collaborating with the Nazis, has long been a disputed territory between the two countries.
However, as far as Greece is concerned, Epirus is no longer an issue of contention.
Greece originally began surveying the area along its border with Albania in 2011 but no official complaint was launched with the Greek authorities at the time.
The deadline for private companies to submit their bids for exploitation rights has been set for mid-June.
According to Greek media, citing diplomatic sources, Greek Foreign Minister Nikos Kotzias is now planning to cancel his scheduled attendance at a meeting of Foreign Ministers at the South-East European Cooperation Process (SEECP) summit on May 22 after receiving the complaint.
Greek Prime Minister Alexis Tsipras, on the other hand, is expected to join the meeting at a later date on May 26.