Belarus on Monday accused the United States of recruiting citizens into a spy ring aimed at undermining the ex-Soviet republic.

The U.S. State Department said the allegation was "just ridiculous" and that the department was considering whether to close its embassy in Minsk.

Tension has been building between Washington and the authoritarian regime of President Alexander Lukashenko, and most U.S. Embassy employees have been expelled in recent months.

Valery Nadtachayev, a spokesman for the main security agency, the KGB, told Belarusian television on Monday that the U.S. Embassy had hired 10 local citizens to take photographs of police officials, airports and villages near the state border.

Most of the diplomats were expelled after the U.S. imposed sanctions on a state-controlled Belarusian company and travel restrictions on President Alexander Lukashenko and other top government officials.

The U.S. Embassy in Minsk declined comment, but in Washington, U.S. State Department spokesman Tom Casey rejected the accusations.

"Other than laughter I really don't have much reaction to it," Casey told reporters. "It's completely unfounded and untrue. They can come up with whatever excuses they like for their totally unjustified and unwarranted (expulsion) of our staff, but I'm sorry, this is just ridiculous."

He said State Department officials were still weighing how to respond to the expulsions, including the possibility of closing the U.S. Embassy.