Douglas McAuthur McCain, 33, of New Hope, Minnesota is pictured in this undated handout photo
Douglas McAuthur McCain, 33, of New Hope, Minnesota is pictured in this undated handout photo.Reuters

The first known American citizen, who left the US earlier this year to fight with the jihadists of the hardliner Sunni militant group, Islamic State, was shot dead during a battle with rival Syrian fighters late last week in Aleppo, according to Syrian opposition officials and the Obama administration.

"We were aware of US citizen Douglas McAuthur McCain's presence in Syria and can confirm his death," US National Security Council spokeswoman Caitlin Hayden said in a statement. "We continue to use every tool we possess to disrupt and dissuade individuals from travelling abroad for violent jihad and to track and engage those who return."

The incident bore a stark reminder of concerns expressed by Pentagon last week on Western fighters who have joined the extremist groups posed one of the greatest risks as they could return to their homeland with a plan for a terrorist attack that could bypass the intelligence.

"The piece that we're very concerned about now... is the threat of foreign fighters who have Western passports, and that's a piece that we're tracking closely as well because we think it could pose a threat to us," State Department spokeswoman Jen Psaki said in a press briefing on Tuesday.

Newspapers have reported citing his cousin, Michael Roland, that the 33-year-old travelled overseas this year before entering Syria. The Mid-western native perished in a fire fight last weekend just days after his fellow terrorist released the video of the beheading of US journalist James Foley.

"It was his destiny," New York Daily News quoted a close relative as saying after news emerged on Tuesday that McCain, was carrying a US passport and $800 cash when he was killed in Aleppo.

In Facebook, the man called himself 'Daule ThaslaveofAllah" and has also posted his religious views in Twitter saying, "Its Islam over everything", the Daily News notes.

According to US officials, McCain is one of dozens of Americans to join the terrorist war against their homeland, and was one of three foreign-born jihadists, including a Tunisian and an Egyptian, killed in the gunfight in the northern Syrian city of Marea, which is administratively part of the Aleppo Governorate, located 25 km north of Aleppo.