The U.S. government said it is “deeply concerned” by Azerbaijan establishing a checkpoint on the only land route to the contested region of Nagorno-Karabakh, saying it undermines efforts toward peace in the region.

“The United States is deeply concerned that Azerbaijan’s establishment of a checkpoint on the Lachin corridor undermines efforts to establish confidence in the peace process”, the U.S. State Department said in a statement.

The State Department urged free and open movement of people and commerce on the Lachin corridor and also called on the parties “to resume peace talks and refrain from provocations and hostile actions along the border”.