More than a year after the deadly attack on the U.S. diplomatic facility in Benghazi, Libya, U.S. law enforcement is still looking for the perpetrators of the attack.

A top U.S. State Department official acknowledged at a congressional hearing Wednesday that U.S. agents aren't being allowed into Benghazi, after The New York Times reported last week that the Libyan government was not allowing arrests.

"Benghazi has taken, even since the events of 9/11 [the date on which the attack occurred, in 2012] a serious turn for the worse," Under Secretary of State for Management Patrick Kennedy told the House Foreign Affairs Committee Wednesday. "Yes, they will let journalists in, but they are not letting U.S. law enforcement in to arrest people there because the government of Libya is not in control to that degree."

The FBI has been handling the investigation into the Benghazi attack that resulted in the death of U.S. Ambassador J. Christopher Stevens, and President Obama has publicly vowed to find the perpetrators.