A federal grand jury in New York has already indicted al Libi for the embassy attacks.
State Department rules out Guantanamo
But trying terrorism suspects on American soil has been a controversial topic in the past.
In 2009, Attorney General Eric Holder said five Guantanamo Bay detainees with alleged ties to the 9/11 attacks would be transferred to New York for trial in civilian court. Later Holder reversed course, announcing that accused 9/11 mastermind Khalid Sheikh Mohammed and others would be tried in a military commission at Guantanamo instead.
Could al Libi face a similar fate?
State Department deputy spokeswoman Marie Harf said Monday that there's no chance he could end up at Guantanamo.
"The administration's position on Guantanamo is clear. Our goal is not to add to the population, it's to reduce it, which we've done. ... Our policy is not to send any new detainees to Guantanamo," she said.
Concern grows over terrorism in region
The weekend attacks come as concern over terrorism in the region is on the rise after last month's deadly shopping mall attack in Kenya's capital.
Al-Shabaab claimed responsibility for the attack, which left at least 67 people dead.
A U.S. official said Monday that the U.S. government is concerned about the al Qaeda-linked militant group's growing focus on external operations -- including the possibility of striking U.S. interests in the region.
The Somalia operation was planned before the mall attack, the official said.
Another source underlined that the raid was not in response to the mall attack, adding that the United States has been going after Al-Shabaab for some time, with SEALs and with drones.