Turkish Defense Minister Hulusi Akar asked Greece to “demilitarize” 16 Aegean islands near Turkey as he claims they have been illegally armed, in a move that may exacerbate strains in the countries’ relations.

“We expect Greece to act in line with international law and the agreements it has signed”, state-run Anadolu Agency cited Akar as saying in Ankara on Wednesday.

The two neighbors are already at loggerheads over offshore natural-gas reserves in the eastern Mediterranean. Tensions over conflicting claims have escalated since Turkey and Libya signed a contentious agreement last year that delineates maritime borders and affirms claims of sovereignty over areas of the Mediterranean.

Turkey’s claims could make it more difficult and costly to build a planned natural-gas pipeline that could link the eastern Mediterranean basin with European markets through Cyprus, Greece and Italy.

Greece and Turkey, both NATO members, came close to conflict in 1996 over a pair of uninhabited islets in the Aegean.

Source: Bloomberg