A US judge has sentenced an American woman who called herself "Jihad Jane" to 10 years in prison - at least a decade less than prosecutors had sought for her role in a failed plot to kill a Swedish artist for his anti-Islam drawings.

Colleen R LaRose, 50, who converted to Islam online and has maintained her faith, was given credit for the four years she has already served. LaRose, who pleaded guilty to following orders in 2009 from alleged Al Qaeda operatives, could have received a life sentence.

"It's a just and reasonable sentence," her attorney, Mark Wilson, told reporters after the hearing. "She's pleased. Ten years is about what we were hoping for all along."

US District Judge Petrese Tucker called LaRose's crimes "gravely serious," adding: "The court has no doubt that, given the opportunity, Ms. LaRose would have completed the mission."

Tucker also cited the significant cooperation LaRose has given the Federal Bureau of Investigation in other terrorism cases since her 2009 arrest, as well as the sexual and other abuse she suffered as a child. That abuse was chronicled in a 2011 Reuters investigative series.

LaRose, who used the name Jihad Jane as she became involved in the Muslim online community, traveled to Europe in 2009 intending to participate in a militant plot to shoot artist Lars Vilks in the chest six times. But LaRose became impatient with the men who lured her to Europe and she gave up after six weeks and returned to Philadelphia, where she was arrested.

At Monday's hearing, LaRose apologised for blindly following the instructions of her handlers. "I was in a trance and I couldn't see anything else," she said. "I don't want to be in jihad no more."

While LaRose was in contact with an al Qaeda operative in Pakistan, her conspirators repeatedly bungled a plot that never moved much past the planning stages. Vilks, the artist, had told Reuters that he believes LaRose has spent enough time in prison and should be freed.

"That's a pretty tough sentence," Vilks told the Swedish news agency TT on Monday.

Ali Damache, LaRose's alleged handler in Ireland, remains jailed there, fighting extradition to the US on terrorism charges. Jamie Paulin Ramirez, who flew from Colorado to marry Damache in Ireland, has pleaded guilty to related terrorism charges and is scheduled to be sentenced on Wednesday.

The sentencing for another co-conspirator who has pleaded guilty, Mohammad Hassan Khalid, has delayed in order to complete psychological evaluations. Khalid, who grew up in Pakistan and was an honor student in suburban Baltimore, committed his crimes when he was 15 and 16. He is the youngest person ever charged with terrorism inside the US. - Reuters