Armenia and the United States began a joint military training exercise on Monday, both sides said, at a time of high tension in Armenian relations with neighbouring Azerbaijan.

The 10-day “Eagle Partner” exercise involves 85 US and 175 Armenian soldiers and is designed to prepare the Armenians to take part in international peacekeeping missions. It is taking place at two training grounds near the capital Yerevan.

The Armenian defence ministry said on Monday that “the purpose of the exercise is to increase the level of interoperability of the unit participating in international peacekeeping missions within the framework of peacekeeping operations, to exchange best practices in control and tactical communication.”

Though small in scale, the drill has irked Russia, which has a military base in Armenia and regards itself as the prime security guarantor in the region.

Armenia and neighbouring Azerbaijan have fought two wars in the three decades since the collapse of the Soviet Union, and each side has accused the other within the past week of building up troops near the border.