Nabil bin Jab Allah, 39, “had set light to a gas canister but was only slightly injured” when his van caught fire after slamming into the embassy wall overnight on Monday, said officials on Tuesday.
Bin Jab Allah told investigators that he “wanted to commit suicide after he failed to obtain a visa which would have allowed him to return to the United States and be with his American wife”.
Consular staff confirmed to AFP that there had been an accident outside the embassy premises overnight, but made no further comment.
The perimeter wall bore no signs of the accident on Tuesday, but security had been stepped up outside the embassy.
Two extra police cars and members of Tunisia’s national guard were deployed, along with the usual security outside the embassy, which lies on the road linking Tunis to the northern suburb of La Marsa.