US intelligence chief James Clapper has said the law that allows American government agencies to collect communications from internet companies only permits the targeting of "non-US persons" outside the United States.
The response comes after The Guardian reported The National Security Agency had obtained direct access to the systems of Google, Facebook, Apple and other US internet giants, as part of a previously undisclosed program called PRISM.
PRISM allows officials to collect material including search history, the content of emails, file transfers and live chats.
Mr Clapper, the director of national intelligence, said in a statement the story, which also appeared in the Washington Post, contained "numerous inaccuracies," but did not offer any details.
Previously the Guardian reported the NSA is collecting the telephone records of millions of US customers of Verizon, one of America's largest telecoms providers, under a top secret court order issued in April.
The Foreign Secretary said British intelligence would never use its partnership with the United States to get around UK laws.
GCHQ (Government Communications Headquarters) is one of three UK intelligence agencies that form the UK's security and intelligence system.
Facebook, Google and Microsoft have all denied claims that they cooperated with US intelligence agencies to gather data on foreign users.