(Reuters) - Planned joint military exercises by Azerbaijan and the United States were cancelled on Monday against a backdrop of strained ties between Washington and the oil-producing former Soviet republic.
The announcement by Azerbaijan followed its sharp criticism of Washington's role in its festering conflict with Armenia over the breakaway mountain region of Nagorno-Karabakh.
Diplomats say the criticism reflects Azeri anger over U.S. support for a deal between Armenia and Azerbaijan's close Muslim ally Turkey to mend ties and reopen their border. Azerbaijan, a supplier oil and gas to the West, fears the deal will weaken its hand in talks over the rebel territory.
Azerbaijan did not specify who cancelled the exercises planned for May, or why, but the U.S. embassy said it suggested "that the question be posed to the government of Azerbaijan".
An Azeri Defense Ministry spokesman told Reuters: "The exercises are cancelled, but the reason is not known."
In an interview with Reuters on Friday, a senior aide to Azeri President Ilham Aliyev accused the United States of siding with Armenia in the Nagorno-Karabakh conflict and warned that Baku could "reconsider" its relations with Washington.
The United States is co-mediator with Russia and France in talks over the rebel region, where ethnic Armenians backed by Armenia threw off Azeri rule in the early 1990s in a war that killed 30,000 people. A peace deal has never been signed. Turkey closed its frontier with Armenia in 1993 in solidarity with Azerbaijan during the war, and Azerbaijan says it should stay closed until ethnic Armenian forces pull back.
Despite misgivings over human rights under Aliyev, the United States has traditionally had good relations with Azerbaijan, which hosts oil majors including BP, ExxonMobil and Chevron.
Stung by the Azeri backlash, Turkey now says it will only ratify the deal with Armenia if Yerevan makes concessions on Nagorno-Karabakh. Diplomats say the issue is weighing on negotiations between Turkey and Azerbaijan on gas supplies and transit, complicating plans for the U.S. and European-backed Nabucco pipeline.