Russia on Friday summoned the ambassador of Armenia over "unfriendly steps," as Yerevan announced drills with the U.S.

military and has grown increasingly critical of Moscow's role in the Nagorno-Karabakh standoff.The move followed warnings by the Kremlin against conducting drills with the U.S.

and mounting tensions between Armenia and Azerbaijan over the disputed territory. Yerevan, a traditional ally of Russia, has become more vocal in its criticism of Moscow's peacekeeping mission in Nagorno-Karabakh.Russia's Foreign Ministry said in a statement that "the Armenian leadership had in recent days taken a series of unfriendly steps."These included "U.S.

military drills on Armenian territory," a trip to Kyiv by the Armenian Prime Minister's wife and Yerevan's decision to join the International Criminal Court, it added.