Crowley said the "highest levels" of the State Department were aware of the U.S. counterintelligence investigation and the plan to make the initial arrests.
Crowley mentioned no names, but the department's third-ranking official, William Burns, is a former U.S. ambassador to Moscow.
Prosecutors said several suspects were Russians living in the United States under assumed names and posing as Canadian or American citizens.
The Associated Press contributed to this report.
