Greece and the United States signed on Thursday an agreement which renews a long-standing defence cooperation among the two countries.
The two NATO allies, with strong political and economic ties, renewed their agreement for five years.
The United States has several military bases in Greece and the amendment will allow their defence agreement to "remain in force" indefinitely, U.S. Secretary of State Antony Blinken told a news conference in Washington, alongside Greek Foreign Minister Nikos Dendias.
"We're strengthening our defense cooperation today," Blinken said. "This update will allow the agreement to remain in force indefinitely. And it enables our forces in Greece to train and operate from additional locations."
Dendias said that U.S. commitment to Greece showed that both countries are firmly determined to mutually safeguard and protect the sovereignty and territorial integrity of each other.
The agreement, first signed in 1990, has been renewed in successive periods with the last extension occurring in 2019.
Dendias said the renewal "is symbolically and substantially the foundation of our long-term partnership."
"You're underlining that the United States, as well as Greece, are firmly determined to mutually safeguard and protect the sovereignty and territorial integrity of each country against actions threatening to peace, including armed attacks or threats thereof," he said.
The extension comes one week after the Greek parliament ratified a pact with France which states Greece will purchase three French frigates that will be delivered in 2025 and 2026. It also includes security cooperation between the two countries, a move hailed by both sides as a step toward European strategic autonomy.
Greek Prime Minister Kyriakos Mitsotakis has emphasized that the agreement includes mutual defense assistance in the event of an attack on either county by a third, referring to the "casus belli" declared by the Turkish National Assembly in 1995.
Greece has been at odds with Turkey over the extent of their continental shelves and their maritime boundaries.