'Underwear' bomber sentenced to life term in prison.
Booking photograph of Umar Farouk Abdulmutallab from the US Marshals Service on 28/12/2009. Reuters

Umar Farouk Abdulmutallab has been sentenced to life without parole by a US judge for attempting to blow up a US-bound aircraft on Christmas Day 2009.

Abdulmutallab was on a suicide mission for al-Qaida when he boarded the Northwest Airlines flight 253 with a bomb sewn into his underwear. Three hundred people were on board the Christmas Day flight from Amsterdam to Detroit.

The 25-year-old Abdulmutallab was badly burned when the bomb did not detonate properly.

"This was an act of terrorism that cannot be quibbled with," judge Nancy Edmunds said.

"Abdulmutallab has never expressed doubt or regret or remorse about his mission. In contrast, he sees that mission as divinely inspired and a continuing mission."

Hailing from a wealthy Nigerian family, Abdulmutallab was an engineering student at University College London. He is the son of a Nigerian banker, Alhaji Umaru Mutallab.

Throughout the judgment, Abdulmutallab did not show any remorse for his actions and looked uninterested, the Guardian reported.

"Mujahideen are proud to kill in the name of God. And that is exactly what God told us to do in the Koran. Today is a day of victory," Abdulmutallab declared during the trial.

"In quick response to some of the things that have been said, I say my life and the lives of Muslims have also changed due to the attacks on innocent civilians."

Abdulmutallab revealed during the trial that he was trained under Anwar al-Awlaki, a radical American-born cleric, and other prominent al-Qaida figures in Yemen.

However, on the second day of the trial, a defiant Abdulmutallab unexpectedly pleaded guilty of all charges.

The family of Abdulmutallab has appealed to the US Justice Department to review his life sentence on the ground that his act has not resulted in any loss of life.

"We are grateful to God that the unfortunate incident did not result in any injury or death," the BBC quoted the family of Abdulmutallab saying.

"We strongly appeal to the American justice department to review the life sentence," they said.