Prime Minister David Cameron stressed UK intelligence agencies operated within the law and were subject to "proper scrutiny" by politicians.
Speaking to ITV News Political Correspondent Libby Wiener Mr Cameron said the UK's intelligence services were necessary to protect citizens in a "dangerous world".
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.