ATHENS (AP) — The chairman of the U.S. Joint Chiefs of Staff has begun a two-day visit to Greece, starting off a week of high-level contacts between the two countries amid increased strain between the United States and Turkey.

Gen. Joseph Dunford arrived Monday and is scheduled to meet his Greek counterpart Adm. Evangelos Apostolakis in Athens Tuesday.

The United States is keen to boost trade and military cooperation with NATO ally Greece as tension with neighboring Turkey continues to escalate over a variety of regional and political disputes.

Later this week, U.S. Commerce Secretary Wilbur Ross is due to visit an annual trade fair in northern Greece, along with Republican Sen. Ron Johnson, who is chairman of the Senate committee of homeland security and subcommittee on European and regional security cooperation.