But Letts said in an online statement he "hated" his parents" because they are non-believers, and called on them to convert.
He added: "They reject the religion of truth, so I reject them. I hate the Kuffaar [non-believers], and am free from them. Die in your rage."
Letts told Channel 4: "I came here searching for the truth, and people of the truth, and I don't regret that I came.
"I searched for the people of truth, and I found a lot of them here. I found people that act on what they learn and teach, and benefited a lot from them, Alhamdulillah (praise be to God)."
When asked if he is an Isis fighter, he said: "Currently I'm not," and added: "I'm not and nor do I agree with lot of what they follow".
In a separate online statement in Arabic, which he said should be remembered as his final words if he is killed, he wrote: "I oppose so-called Islamic State, but that doesn't mean I am with you, the dirty non-Muslims".
Asked if he is a terrorist, he said: "Do you mean by the English Government's definition, that anyone that opposes a non-Islamic system and man-made laws, then, of course, by that definition, I suppose they'd say I'm a terrorist ... "
He said he does not think he would be welcome if he returned to Britain, but that he misses the "small things"- specifically Krispy Kreme doughnuts and kebabs.
Despite a near-miss when he said he narrowly survived an air strike with just a "scratch", the Briton said he is not afraid of death: "I'm not worried. Everyone is going to die on their day. Whether it's by a drone strike. A Muslim understands that his life is between the hands of Allah.
"So if they want to bomb me, they'll bomb me."
