BELGRADE, Serbia (AP) — The U.S. embassy in Belgrade says there's no need to grant a diplomatic status to the Russian staff of the controversial facility in Serbia that some consider a spy base but that Moscow insists is a disaster relief center.

An embassy statement obtained Saturday by The Associated Press says its representatives visited the Nis center, 200 kilometers (120 miles) south of Belgrade, this week.

The statement says "U.S. representatives were briefed on the current functioning of the center, but saw nothing in the activities that were shown which would indicate a need for diplomatic status." It adds "the consistent demands for inviolability for the personnel and premises of the Center only raise question regarding long-term intentions for the facility."

Serbia has been boosting ties with Russia while formally seeking European Union membership.