The Senate passed a military spending measure last week that requires the Pentagon to provide details about where the money will go, exactly, and just what all those spies would be doing, The Washington Post reported Monday.
The Defense Department "needs to demonstrate that it can improve the management of clandestine [human intelligence] before undertaking any further expansion," the bill states.
The measure expresses concerns about existing Pentagon intelligence efforts, including "poor or non-existent career management" for operatives who were trained but wound up on "unproductive" assignments or returned to regular military units.
The Post said the lawmakers' reticence to dole out more money is a setback for the Defense Intelligence Agency, which is working on a five-year plan to develop its espionage network along the lines of the Central Intelligence Agency.
The DIA wants to boost its force of about 500 overseas undercover operatives to between 800 and 1,000 by 2018, officials have said.