A US Air Force veteran allegedly sympathetic to Osama bin Laden and who became a Muslim has been charged for trying to join Islamic State jihadists in Syria, prosecutors said Tuesday.

Tairod Pugh, 47, who had spent the last 18 months living in the Middle East and has an Egyptian wife, allegedly tried to travel to Syria in January weeks after being sacked as a plane mechanic.

It is the fourth arrest announced by Loretta Lynch, a US Attorney General nominee and the current US attorney for the eastern district of New York, over recent plots to join IS extremists fighting in Syria.

Pugh was indicted with attempting to support a foreign terrorist organization for nine months from May 2014 to January, and with obstruction of justice over the tampering of electronic evidence.

He faces up to 35 years in prison if convicted and will appear before federal Judge Nicholas Garaufis in Brooklyn on Wednesday.

Court papers show he cropped up on the FBI's radar as early as 2001 as an American Airlines employee purportedly sympathetic to the Al-Qaeda mastermind responsible for the 9/11 attacks.

Prosecution documents say 180 jihadist videos were found on his laptop, including one showing IS killers shooting a group of prisoners in the head one by one.

It also allegedly contained information on crossing points into Syria and a letter to his wife calling himself a "mujahid" -- or holy warrior -- who faced either victory or martyrdom.

US intelligence officials say more than 20,000 volunteers from around the world, including more than 150 Americans, have gone to Syria to link up with extremists.

Pugh served in the US Air Force from 1986 to 1990 as an instrument specialist and was trained in aircraft engine, navigation and weapons systems maintenance.

In 1998, he moved to Texas, converted to Islam and "became increasingly radical in his beliefs," according to the complaint.

- 'Turned his back on his country' -

By 2001 -- the year that Al-Qaeda hijacked US passenger jets -- he was working as a mechanic for American Airlines.

That year, the FBI received a tip from a co-worker alleging he was sympathetic to bin Laden and that he claimed the 1998 Al-Qaeda bombings of US embassies in East Africa, which killed 224 people, were justified.

In 2002, "an associate" subsequently told the FBI that Pugh had wanted to travel to Chechnya to fight jihad.

Court papers next put him in Iraq, where he worked for around six months in 2009-2010 on aircraft avionics for DynCorp, a private contractor to the US military.

From New Jersey, for the last year and a half before his arrest, he is believed to have been living in Egypt, Dubai and Jordan.

"Born and raised in the United States, Pugh allegedly turned his back on his country and attempted to travel to Syria in order to join a terrorist organization," said Lynch.

"We will continue to vigorously prosecute extremists, whether based here or abroad, to stop them before they are able to threaten the United States and its allies."

Prosecutors say Pugh was stopped by Turkish guards at Istanbul airport after flying in from Egypt on January 10, when he allegedly said he was a US Special Forces pilot on vacation.

Suspicious, they sent him back to Cairo, where he was detained, his laptop found damaged and inoperable, his iPod wiped clean of data and USB thumb drives also intentionally damaged.

He allegedly told Egyptian authorities that he would rather be deported anywhere in the Middle East because "the US doesn't like black Muslims" and when asked how he would pay for his flight home, said he would prefer to remain in Egyptian custody.

He was arrested on January 16 in the United States and indicted by a federal grand jury in Brooklyn on Monday.