Al-Qaeda chief Osama bin Laden has sought and wanted to use nuclear arms, former bodyguard Nasser al-Bahri said in an interview with an Arab daily published on Wednesday.

"Sheikh Osama used to dream of possessing nuclear weapons, and I am sure that if he were to get his hands on a nuclear weapon, he would not have hesitated to use it," the Yemeni guard told the London-based Al-Quds Al-Arabi.

The United States warned earlier this month that Al-Qaeda's interest in nuclear weapons was still strong and said the risk of nuclear terrorism was serious.

"Al-Qaeda has been engaged in the effort to acquire a nuclear weapon for over 15 years, and its interest remains strong today," said John Brennan, President Barack Obama's top anti-terrorism and Homeland Security advisor.

But Brennan said he had "no indication that Al-Qaeda has a nuclear weapons capability."

Bahri, who now lives in Yemen with two wives and five children, said he was "proud to have worked as a guard for a great personality," saying he was instructed to kill Bin Laden if that was the only way to avoid his capture.

Bin Laden has a 50-million-dollar US bounty on his head.

"If we were not able to protect Sheikh Osama bin Laden as his personal guards, we were supposed ... to eliminate him ... It was better he be taken dead rather than alive," he said.

"That would be a massive defeat for Al-Qaeda, jihadist groups and Muslims in general," he added.

But the former guard, who left Al-Qaeda and Afghanistan in 2000, told AFP earlier this month that he had co-authored a book with a French journalist aimed at dissuading young people from joining Al-Qaeda.

As a supporter of jihad, or holy war, against what he considered "Western injustice," Bahri had joined Al-Qaeda but found it "not very convincing from the inside," he said.

Bahri served time in detention in Yemen following the October 2000 suicide bombing against the warship USS Cole in the southern port of Aden that killed 17 American personnel.