US Secretary of State Mike Pompeo arrived in Athens on Friday evening, where he was greeted by Greek counterpart Nikos Dendias.
On Saturday, the US official will meet Prime Minister Kyriakos Mitsotakis, Dendias and Defense Minister Nikos Panagiotopoulos.
At 12:30, Dendias and Pompeo will discuss bilateral and regional issues at the ministry of foreign affairs and sign the Protocol of Amendment to the Mutual Defense Cooperation Agreement (MDCA).
The new deal establishes the operational framework of the US presence at the northern Greek port of Alexandroupoli, which Greece sees as being of significant geostrategic value.
It also outlines the terms of operation at Marathi at the Souda base on Crete and also ensures the establishment of high-technology installations on Greek soil and within Greek bases and camps in central Greece.
The head of US diplomacy is visiting Athens after travelling to Italy, Montenegro and North Macedonia.