"The (Greek) defence minister will receive a draft letter of acceptance on Monday," one of the sources said.

Greece sent an official request to the United States for the purchase of 20 Lockheed Martin-made F-35 fighter jets in June 2022.

Getting that request approved is a crucial step in a multi-stage process. Athens expects deliveries of the jets to begin in 2027-2028.

NATO member Greece spends more than 2% of its gross domestic product on defence spending. It has beefed up its military purchases in recent years as tensions with its neighbour, historic rival and NATO ally Turkey, had resurfaced.

U.S. President Joe Biden sent a letter to leaders of key Capitol Hill committees on Wednesday informing them of his intention to begin the formal notification process for the sale of Lockheed Martin (LMT.N) F-16 aircraft to Turkey once Ankara completes Sweden's NATO accession process.

(Reporting by Lefteris Papadimas; Writing by Renee Maltezou; Editing by Mark Porter)