FILE - A handout photo released by the Greek National Defense Ministry Aug. 26, 2020, shows ships of the Hellenic Navy taking part in a military exercise in the eastern Mediterranean Sea, Aug. 25, 2020.
FILE - A handout photo released by the Greek National Defense Ministry Aug. 26, 2020, shows ships of the Hellenic Navy taking part in a military exercise in the eastern Mediterranean Sea, Aug. 25, 2020.

U.S. Secretary of State Mike Pompeo called on NATO allies Greece and Turkey Tuesday to resume talks as soon as possible to settle an increasingly contentious maritime territorial dispute in the Mediterranean Sea.

The two countries, which are at odds over multiple issues, have agreed to exploratory negotiations regarding an area in the eastern Mediterranean where their warships faced off last month.

Turkey sent a research vessel that was accompanied by warships to search for possible oil and gas drilling in an area that Greece claims territorial and economic rights. Greece responded by sending warships to the area and putting its military on alert, fueling fears of conflict.

Turkey has since recalled the ship, saying the move would clear the way for more talks before a two-day European Union summit that begins on Oct. 1. EU members will address the territorial disagreement and also discuss possible sanctions against Turkey that have been demanded by Cyprus, Greece and France.

“We hope that these talks can continue in a serious way,” Pompeo said, following a meeting with Greek Prime Minister Kyriakos Mitsotakis on the island of Crete. “[We] encourage them to resume discussion of these issues as soon as possible.”

FILE - A handout photo released by the Turkish Defense Ministry Aug. 12, 2020, shows Turkish seismic research vessel Oruc Reis (C) as it is escorted by Turkish Naval ships in the Mediterranean Sea, off Antalya, Aug. 10, 2020.

Eastern Mediterranean countries hoping to find oil and gas have been rushing to claim jurisdiction over maritime areas, reviving decades-old conflicts in the search process.

Greece and Egypt have agreed to a deal defining maritime boundaries between them, to the consternation of Turkey, which contends the pact encroaches on its territory. A similar agreement between Turkey and the Libyan government has, in turn, angered Turkey.

Pompeo embarked on a two-day trip to Greece after the regional escalation of tensions over energy resources. He said the U.S. supports Greece’s efforts to diversify access to routes to energy sources and energy supplies. Pompeo added that Russia is a destabilizing influence in the area.

His visit to Greece is part of a five-day regional tour that will also take him to Croatia, Italy and the Vatican.

A senior State Department official traveling with the Secretary told reporters he would travel to Turkey at the end of the trip, to Istanbul and Ankara to meet with Turkish counterpart, since the Secretary has to get back to Washington. The official told reporters: "Our position has been very clear all along, about the need to avoid escalation, to de-escalate and return to talks, not take unilateral actions, and to look for a negotiated settlements to these issues like maritime boundaries." 

Wayne Lee contributed to this report.