Osama bin Laden's son-in-law and former Al-Qaeda spokesman was jailed for life on Tuesday after a US judge warned he remained a deadly threat to American citizens.Kuwaiti national Sulaiman Abu Ghaith, 48, was handed the sentence after being convicted by a federal court in New York in March of plotting to kill Americans and providing material support to terrorists. Before the sentencing, Abu Ghaith -- who had applauded the September 11, 2001 attacks in propaganda videos after the strikes -- spoke in Arabic through a translator to say the only judgment he would accept was that of God."Today when you are shackling my hands, and intend to bury me alive, you are unleashing the hands of hundreds of Muslims and they will join the rally of free men," he said, dressed in a dark prison outfit.
Judge Lewis Kaplan said Abu Ghaith failed to show remorse for the September 11 attacks which left nearly 3,000 people dead, and told the courtroom he remained a menace.
"You continue to threaten," Kaplan said. "You sir, in my assessment, still want to do everything you can to carry out Al-Qaeda's agenda of killing Americans."
"What you have done warrants the maximum sentence," he added.
- Plan to appeal -
US Attorney General Eric Holder hailed the judgment, and promised Abu Ghaith would "never again set foot outside a prison cell."
"Justice has been served," Holder said.
Senate Intelligence Committee chief Dianne Feinstein said the sentence "reminds the world that the United States will continue to capture and punish our enemies."
Abu Ghaith's lawyers, who plan to appeal the ruling, asked for a 15-year sentence, arguing that he served 11 years in detention in Iran.
His fiery anti-American diatribes were aired in court before a 12-person jury, which spent four hours deliberating before settling on a guilty verdict earlier this year.
His lawyers downplayed his role in the attacks and said that while he may have been guilty of "obnoxious, sometimes hateful" speech, he was not involved in the plot.
In a September 12, 2001 video, Abu Ghaith is seen sitting alongside bin Laden and current Al-Qaeda leader Ayman al-Zawahiri justifying the 9/11 attacks and promising more bloodshed.
In October 2001, he repeated his threat, vowing "the storm of the planes would continue" in a video message.
While he admitted to appearing in the post-September 11 films, Abu Ghaith said he did not recruit anyone and never plotted to kill Americans.
Instead he said he was denouncing the "oppression" of Muslims.
But the top federal prosecutor in Manhattan, Preet Bharara, called him "the mouthpiece of murder and menace for Al-Qaeda."
- On the move -
Abu Ghaith arrived in Afghanistan in 2001 and was allegedly responsible for motivating recruits in Al-Qaeda training camps.
He remained in the country and worked as a spokesman for the group until moving to Iran in 2002.
He was arrested the following year and married bin Laden's daughter in 2008 while in prison.
After spending more than 10 years in prison, he went to Turkey, where he was arrested in late 2013, his lawyers said.
He was later deported to Jordan and was arrested and extradited to the United States.
Abu Ghaith is the highest-ranking Al-Qaeda operative ever held in a prison on US soil.
The alleged mastermind of the attacks, Khalid Sheikh Mohammed, is currently in US custody in Guantanamo Bay alongside four suspected co-conspirators.
They could face the death penalty if convicted.