U.S. President Barack Obama nominated Matthew Olsen on Friday as the director of the National Counterterrorism Center to replace Michael Leiter, who resigned, according to Reuters. Olsen has been general counsel at the National Security Agency, one of the top U.S. spy agencies. "Matt will be a critical part of my national security team as we work tirelessly to thwart attacks against our nation and do everything in our power to protect the American people," Obama said in a statement. The counterterrorism center was created after the Sept. 11, 2001, attacks to improve the sharing of intelligence among competing U.S. spy agencies. Leiter had been in the job for 4 1/2 years. The position requires U.S. Senate confirmation.