Director of U.S. National Intelligence James Clapper has refuted criticism that the intelligence community failed to adequately monitor or predict recent events in Egypt and the region.
Clapper told the House Intelligence Committee Thursday that intelligence officials are closely following the anti-government uprisings in the Middle East.
He also said nuclear proliferation is a major threat to the United States and its allies, citing in particular North Korea and Iran.
Clapper's testimony is part of the U.S. intelligence community's annual worldwide threat assessment.
CIA Director Leon Panetta and FBI Director Robert Mueller are also testifying.
The officials will later participate in a closed session with the committee.
The Republican-led House has been discussing how to trim the federal budget. Last year, the government announced it spent more than $80 billion on intelligence activities, double what it spent before the September 11, 2001, attacks on the United States.
On Wednesday, U.S. Homeland Security Secretary Janet Napolitano told the House Homeland Security Committee that the terrorist threat against the United States is evolving and, in some ways, is at its most heightened state since the 2001 attacks.
She said her department is working to provide state and local law enforcement with the information and resources they need to combat the threat of violent extremism within their communities.