Sitting under a Kurdish flag and fidgeting with his hands, the first known American fighter to purportedly defect from the Islamic State explained on Kurdish TV that joining the terror group was "a bad decision" and that he quickly became dissatisfied with life under the militant group's rule.

Mohamad Khweis, a 26-year-old from Virginia, surrendered to peshmerga militiamen near Sinjar in Iraq in the early hours of Monday morning. Khweis reportedly traveled from the United States to Europe in December. He crossed over the Turkish-Syrian border before ending up in Mosul, which has been under IS occupation since July 2014.

In an exclusive interview Khweis told Kurdistan 24 that, "It was pretty hard to live in Mosul."

"It's not like Western countries," Khweiss said . "It is very strict and [there's] no smoking."

Khweis said he spent almost his entire day in religion classes. "Our daily life was basically prayer, eating, and learning about the religion for about eight hours."

He quickly grew disillusioned, and failed to complete his training course in Sharia law. "I didn't agree with their ideology," Khweis said. "That's when I wanted to escape."

Khweis said he didn't encounter other Americans during his time there – that most other fighters were, "Asian, Russians and people from the surrounding area." The timeline of when exactly he arrived in Syria isn't clear.

Khweis said he left the US in December 2015, and traveled to the United Kingdom. He then went to Amsterdam, and then on to Turkey. In Turkey, he says he met an "Iraqi girl" whose sister who was formerly married to an IS fighter. Together, they were able to find a contact in Syria who could help them plan their journey to IS territory.

"First we took a bus from Istanbul to Gaziantep," Khweis said, referring to a city in Turkey's southeastern Anatolia region. "From there, a driver picked us up and took us to the [Syrian] border." Another taxi picked them up and drove them close to the Iraq border. "We made contact with another person, who helped us get closer to Islamic State."

When they arrived on the front lines of IS territory, the pair were split up into separate vehicles. Khweis said he was taken to Raqqa, Syria. There, he was asked to hand over his identification cards and passports to the people in charge, was given the name "Abu Omar" and then placed in a house with about 70 other foreign fighters. After one week there, he was transferred to Mosul, along with ten others.

The peshmerga militia who first spotted Khweis early on Monday were suspicious at first.

"Our Peshmergas who were patrolling the frontline said they saw something unusual and started firing at it," Sarbaz Hama Amin, a Peshmerga commander in Iraq told Voice of America. "That thing disappeared after we fired at it but our Peshmergas started looking for it."

"After it became light after five am, he screamed at us and told us in English, "Who can talk to me? I want to come to you," the commander added. "But our Peshmergas didn't understand English. He spoke a very limited Arabic and asked if anyone spoke English. After Peshmergas made sure he had no explosives on, we arrested him and took him to the camp where he said he wanted to surrender."

Kweis said he wanted to reach out to the Kurds because he had heard "they're good with Americans."

Overall, he regrets his decision to join IS, and said he "wasn't thinking straight."

"They don't represent the religion," said Kweis. "I don't see them as good Muslims."

According to a report by the Soufan Group, US authorities know of 150 Americans fighting alongside IS in Syria and Iraq — but said unofficial numbers suggested as many as 250 might have joined the group.

In the interview with Kurdistan 24, Khweis says he was the son of two Palestinians who had lived in the US for over 25 years. His father reportedly works as a limo driver, and his mother as a cosmetologist. He said he rarely attended American mosques. His friends have said he hadn't displayed any signs of radicalization. Khweiss was born in Virginia, and graduated in 2007 from Fairfax County's Edison High School. Khweis said he studied criminal justice at a college in the US, but did not specify which institution.

Harrison Weinhold, 27 — a former classmate of Khweis — told the Washington Post that he instantly recognized Khweis in pictures after the news broke earlier this week.

"I'm like, 'I can't even comprehend what I'm looking at right now'," Weinhold said. "It could not have been a more normal guy." Weinhold said he remembered Khweis for often wearing designer Nike Jordan shoes. Weinhold also said that there were many devout Muslims who attended their school – but that Khweis wasn't one. "He was somebody that joked around," Weinhold said. "And even made fun of people that were super-religious."

Earlier this week, Khweis' father, Jamal Khweis, turned a hose on reporters gathered in the front yard of his Virginia townhouse. "I have nothing to say" he said. "I don't know anything about my son." He said he had spoken to the FBI and had no idea where his son was.

Mohamad Khweis is reportedly under investigation, and what happens next isn't clear. The FBI have said they didn't have him on their watchlist before he surrendered.