Two congressmen say a classified Pentagon report on former National Security Agency systems analyst Edward Snowden asserts that most of the documents he took concerned current military operations.
"The vast majority of the material was related to the Defense Department, and our military services," not NSA operations, House Intelligence Chairman Mike Rogers said in an interview Thursday.
"Clearly, given the scope and the types of information, I have concerns about operations that would be ongoing in Afghanistan," Rogers said, as well other ongoing military operations.
The ranking committee member CA Dutch Ruppersberger said Snowden tipped off US enemies to spying methods used to defend the country, and potentially jeopardized US troops overseas.
They said the classified report by the Defense Intelligence Agency found that Snowden stole approximately 1.7 million intelligence files that "concern vital operations of the US Army, Navy, Marine Corps, and Air Force."
A lawyer representing Snowden said the US government is exaggerating the potential harm of Snowden's actions.
"There is not a shred of evidence that any adversary has seen any documents other than those that have been published by journalists who had access to this material," said Ben Wizner, a lawyer with the American Civil Liberties Union.
Glenn Greenwald, a journalist who received documents from Snowden and reported about them last year for the newspaper The Guardian, said in a statement that "the overwhelming majority" of documents he had received dealt with NSA surveillance on the communications and online activities of American citizens and others around the world.
"As every journalist who has worked with Snowden has said, he was adamant that we very carefully review the materials he gave us and only publish what is in the public interest, while withholding anything that would endanger the lives of innocent people or invade people's privacy," Greenwald said. "We have fully honored our agreement with him when publishing and intend to continue doing so."
Quoting the classified Pentagon report, Rogers and Ruppersberger said the disclosures have already tipped off US adversaries to US defense methods, and hurt US allies helping with counterterrorism, cybercrime, trafficking, and stopping weapons of mass destruction.
They offered no specifics and none of the documents that have been published so far through Snowden associate Glenn Greenwald appeared to have dealt with current military operations.
Director of National Intelligence spokesman Michael Birmingham said intelligence officials are continuing to assess damage from the material Snowden took when he left the country in June 2013.
"We've been clear that these leaks have been unnecessarily and extremely damaging," he said in a statement Thursday.
"As a result of these disclosures, terrorists and their support networks, now have a better understanding of our collection methods and, make no mistake about it, they are taking countermeasures," he said.