URGENT: U.S. intelligence officials knew within 24 hours of the assault on the U.S. Consulate in Libya that it was a terrorist attack and suspected Al Qaeda-tied elements were involved, sources told Fox News -- though it took the administration a week to acknowledge it. 

The account conflicts with claims on the Sunday after the attack by U.S. Ambassador to the United Nations Susan Rice that the administration believed the strike was a "spontaneous" event triggered by protests in Egypt over an anti-Islam film. 

Two senior U.S. officials said the Obama administration internally labeled the attack terrorism from the first day in order to unlock and mobilize certain resources to respond, and that officials were looking for one specific suspect. 

In addition, sources confirm that FBI agents have not yet arrived in Benghazi in the aftermath of the attack.

Fox News' Bret Baier contributed to this report.