Turkey and Azerbaijan have launched joint military exercises lasting from May 1 to May 5 with about 1,000 troops participating, Baku's Defense Ministry says.
The exercises involve testing military equipment and practicing coordination between the two armies, the ministry said.
Azerbaijan's breakaway province of Nagorno-Karabakh, which has a majority Armenian population, sharply criticized the exercises.
"If there are provocations, we will react," David Babajan, spokesman for the region's ethnic Armenian leadership, told dpa.
Armenian separatists declared their independence from Azerbaijan in the 1990s and formed the unrecognized Nagorno-Karabakh Republic, which includes some of Azerbaijan's seized borderlands.
Despite a cease-fire dating from 1994, there are regularly clashes on the heavily fortified frontier, with some 120 people dying in a deadly clash a year ago.
Relations between Turkey and Armenia have been strained for decades over the mass killing and deportation of some 1.5 million Armenians during World War I by the Ottoman Empire.
The atrocities suffered by the Armenians have been classed as genocide by more than a dozen states, but Turkey denies that the mass killings amounted to genocide.