After threatening Greece to pay a "heavy price", the European Union is concerned about Erdogan's statements, describing them as "hostile"

The European Union expressed on Monday its "grave concern" over what it described as "hostile statements" made by Turkish President Recep Tayyip Erdogan against Athens a few days ago regarding islands near Turkey that fall under Greek sovereignty.

Erdogan threatened Greece - in a speech last Saturday to a crowd in the Black Sea region - that it would pay a "heavy price", accusing it of violating Turkish airspace and "harassing" Turkish aircraft over the Aegean Sea.

"Your occupation of the islands (the Aegean Sea near Turkey) does not oblige us. When the moment comes, we will do what is necessary, we may arrive suddenly during the night," he said, repeating a phrase he often used to launch operations in Syria.

"We have one word for Greece: Do not forget about Izmir," he added, referring to the city on the Aegean Sea that the Greeks call "Smyrna".

Greece occupied Izmir, after it was annexed by a treaty at the end of World War I, which Turkey has never recognized. Then the Turks regained this city in 1922 in a battle that is considered pivotal in modern Turkish history.

"These hostile statements by the Turkish political leadership against Greece and the Greek people are of grave concern," said Peter Stano, spokesman for the EU's foreign policy chief, in response to a question during his daily press conference.

"We expect Turkey to refrain from verbal escalation, and to commit to improving good-neighborly relations," he added.

"In relations with Greece, any outstanding issues must be addressed peacefully, through dialogue in good faith, in accordance with international law and in accordance with the principle of good-neighbourly relations," he added.

He pointed out that "Greece is a member state of the European Union, and the sovereignty and territorial integrity of the member states of the European Union must be respected," as he put it.

It is noteworthy that Ankara announced last Sunday that its planes, which were on a mission in the Aegean Sea and the eastern Mediterranean, were targeted by Greece with the S-300 air defense system, denouncing this "hostile act."

Athens accuses Turkish planes of flying over the Greek islands close to the Turkish border, while the dispute between the two neighbors leads to frequent patrols.

Turkey also denounces the presence of military forces on these islands, in violation of the peace treaties signed after the First and Second World Wars, according to its view.