A former Army friend of a New Zealander who has been named on a global terrorism list says the man is a lost soul and harmless.
Mark John Taylor, originally from Hamilton, has been named by the United States government as someone who has committed, or poses a significant risk of, committing a terrorist attack against the United States.
The State Department said Taylor, 43, had been fighting in Syria with IS since late 2014, and appeared in a 2015 propaganda video to encourage attacks in Australia and New Zealand.
Taylor, along with four others, faces sanctions, with US citizens forbidden from having any dealings with him.
Former Army friend Logan Bartlett met Taylor in 1997 when they were both based at the Artillery Headquarters in Waiouru.
Mr Bartlett said he struggled to believe Taylor was dangerous.
"I would have described him as fairly harmless, probably lost. He was a super nice guy, and I don't think he has it in him to do anything particularly dangerous. He's just fallen in with the wrong crowd."
Mr Bartlett said Taylor was seeking meaning in his life.
"Maybe they value him, or he's one of those people who has to be needed, or he's lacking something in his life, so he wanted to find a purpose. But obviously, he chose the wrong sort of route."
A foreign policy expert said Taylor's life was at risk after he was put on the global terrorism list.
Prime Minister Bill English said he was confident security agencies could deal with any risk posed by Taylor if he returned to New Zealand.
Mr English said if Taylor tried to return to New Zealand, security authorities would assess his risk at the time.
He said he could not say how many other New Zealanders could be fighting in Syria.
"I'd be surprised if someone could return home, having been radicalised, without New Zealand finding out appropriately about that at some stage. But it is possible that this Kiwis with New Zealand citizenship in that situation."
Otago University Professor Robert Patman said the 43-year-old, who was believed to be in Raqqa, Syria, was now facing persecution from the US government.
He said anyone associated with Mr Taylor was also at risk.
The US State Department said Taylor had been fighting in Syria with IS since the fall of 2014, and has appeared in a 2015 propaganda video to encourage attacks in Australia and New Zealand.
The department said his aliases included Mohammad Daniel, Abu Abdul Rahman and Mark John al-Rahman.
He was believed to be in Raqqa, Syria.
The US state department said: "Taylor is a New Zealand national who has been fighting in Syria with ISIS since the fall of 2014. Taylor has used social media, including appearing in a 2015 ISIS propaganda video, to encourage terrorist attacks in Australia and New Zealand."
A spokesperson for Chris Finlayson, the Minister responsible for intelligence and security agencies, said the US had kept the New Zealand government informed on the issue.
The US told the government in advance that it was going to designate Taylor a terrorist.
Taylor dubbed the 'bumbling jihadi'
Taylor was detained and deported from Pakistan in February 2009 on suspicion of links with militants.
In 2011, Wikileaks published documents saying Taylor had links to al-Qaeda. John Key, who was Prime Minister, responded by saying the Kiwi public had nothing to fear from Taylor, who, Mr Key said, was at that time living in New Zealand under restrictions.
According to reports, Taylor last year set up a LinkedIn account calling himself an "education management professional" in Syria and previously communicated with journalists over social media.
Twitter has suspended Taylor's account.
Media dubbed him the "bumbling jihadi" in 2014 after he revealed his location to intelligence agencies by tweeting with his geotagging tracking function still switched on.
In 2015 he put a video on YouTube calling for terrorist action in New Zealand. It was removed after only a few views.