As Greece’s Parliament unanimously approved a bill from the ruling New Democracy government to double the country’s territorial waters along its western coastline from six to 12 nautical miles, Turkey warned against doing so in the Aegean.

They are dueling over rights to those waters as well as in the East Mediterranean with Turkey planning to again send an energy research vessel and warships off the Greek island of Kastellorizo and said it would do so off Crete as well.

That’s despite the two countries set to have officials meet in Constantinople on Jan. 25 for a 61st round of exploratory talks for the first time in four years, with Greece this time wanting it limited to discussion of the seas, Turkey wanting other issues on the table, including demands Greece remove troops off islands near Turkey’s coast.

“The extension of territorial waters in the Ionian Sea by Greece to 12 nautical miles reaches up (to) the south of the Peleponnesian Peninsula and does not affect the Aegean Sea in any way,” said Turkish Foreign Ministry spokesman Hami Aksoy.

“Turkey has vital rights and interests in the semi-enclosed Aegean Sea, where special geographical circumstances prevail. Turkey’s position that the territorial waters in the Aegean Sea should not be unilaterally extended in a way to restrict the freedom of navigation as well as the access to the high seas of both Turkey and third countries, is well-known by all parties. Our position remains unchanged,” he added.

Before the 284-0 vote – `6 Communist lawmakers didn’t vote – Prime Minister Kyriakos Mitsotakis said during a debate that Greece was exercising its sovereign rights in the Ionian, after discussions with Albania and Italy who share those waters.

He also said Greece had the right to extend its territorial seas elsewhere, including off Crete after Turkey made a maritime deal with Libya dividing the waters between them, Greece countering with a similar agreement with Egypt.

Greece said the vote showed the country’s right to implement the United Nations Convention on the Law of the Sea, which set the 12-nautical mile limit in 1982 but Turkey doesn’t recognize that edict.

“It’s a clear message to those who are trying to deprive our country of this right,” Mitsotakis told Parliament, said Al Jazeera as Turkey earlier warned extending the rights the Aegean would be a cause for war, with disputing claims.

While the vote was seen by Turkey as antagonistic four days before the exploratory talks were due to resume, Mitsotakis said he was still optimistic that differences could be worked out.

After in October, 2020 pulling back his demand for the European Union to sanction Turkey – the withdrawal to give diplomacy a chance, he said – the Greek leader at a December meeting asked for it again but was rebuffed.

Germany, which has lucrative arms deals with Turkey, supplying submarine components that could be used against Greece, blocked the sanctions while holding the EU’s symbolic presidency.

The penalties would be on the table again in March, bloc leaders said, unless Greece and Turkey work out an agreement over the Aegean and in the East Mediterranean where Turkey is drilling for oil and gas in Cypriot waters, defying soft EU sanctions.

As for the Jan. 25 meeting, Mitsotakis said, “We will attend with optimism, self-confidence,” but there would be “zero naivety” about the non-binding talks. “There will be no discussion on national sovereignty,” the prime minister said.

Turkey wants a broader discussion. “It is not right to pick one of those (issues) and say ‘We’re holding exploratory talks’,” Turkish foreign minister Mevlut Cavusoglu said earlier, criticizing Greece’s approach as non-constructive, said Al Jazeera.

Mitsotakis told Parliament if the two sides failed to reach an agreement, they should at least agree on the way the dispute could be referred a judicial body, earlier suggesting the International Court of Justice at The Hague in The Netherlands.

Turkish President Recep Tayyip Erdogan had emphasized the need to “make the Eastern Mediterranean a basin of cooperation that will serve our long-term interests, rather than an area of competition,” between the countries.