U.S. President Barack Obama is unveiling reforms in the vast surveillance being conducted by the country's clandestine National Security Agency.
Mr. Obama said Friday United States intelligence gathering always has "helped secure our country and freedom," but that the 2001 terrorist attacks on Washington and New York posed new challenges.
In a nationally televised address, the president said U.S. intelligence agencies had to adapt to those challenges and modify the surveillance and investigative tactics they had used for decades.
U.S. intelligence has stopped terrorist attacks throughout the world, Mr. Obama said, but concerns that government surveillance might violate civil liberties and privacy need to be accounted for.
Aides say the president plans to end government control of its massive collection of records about telephone calls Americans make, and he will require judicial approval to search the data. In addition, he plans to offer new privacy protections for foreigners whose data is collected by the NSA.
The speech follows months of disclosures about NSA spying by former national security contractor Edward Snowden. The NSA says he stole 1.7 million documents before fleeing to asylum in Russia.