Still image taken from an undated video of Su
Still image taken from an undated video of SuReuters

Osama bin Laden's son-in-law has been detained by U.S. authorities and is due to appear in court in New York on Friday on charges he plotted with the Al-Qaeda leader to stage attacks on Americans, AFP reports.

Sulaiman Abu Ghaith, reportedly a 47-year-old Kuwaiti and allegedly one of the chief propagandists of the Al-Qaeda network, stands accused of conspiring "to kill nationals of the United States," the U.S. State Department said.

Attorney General Eric Holder said the arrest showed that the United States would never relent in its pursuit of the militants who launched the attacks of September 11, 2001.

"No amount of distance or time will weaken our resolve to bring America's enemies to justice," Holder said, according to AFP.

"To violent extremists who threaten the American people and seek to undermine our way of life, this arrest sends an unmistakable message," he said.

"There is no corner of the world where you can escape from justice because we will do everything in our power to hold you accountable to the fullest extent of the law."

Abu Ghaith’s capture is unusual as President Barack Obama's administration has focused on killing Al-Qaeda figures in bombing raids using unmanned drone aircraft, primarily in the tribal belt of Pakistan.

A Turkish newspaper had reported earlier that Ghaith was seized by U.S. authorities at a hotel in Ankara last month and was deported to Jordan, before being taken to the United States.

FBI and CIA officials declined to comment on how Bin Laden's son-in-law ended up in behind bars on American soil.

Republican lawmakers immediately denounced the Obama administration for not sending the suspect to the U.S. military's prison at Guantanamo Bay, Cuba, where he could be held indefinitely and prosecuted under special military tribunals.

"When we find somebody like this, this close to bin Laden and the senior Al-Qaeda leadership, the last thing in the world we want to do, in my opinion, is put them in a civilian court," said Republican Senator Lindsey Graham, according to AFP.

"This man should be in Guantanamo Bay," Graham added.

The chairman of the House Intelligence Committee, Mike Rogers, agreed.

"Al Qaeda leaders captured on the battlefield should not be brought to the United States to stand trial. We should treat enemy combatants like the enemy -- the U.S. court system is not the appropriate venue," Rogers said.

U.S. authorities accuse Ghaith of assisting Bin Laden, the Al-Qaeda chief who was killed in a 2011 raid by American commandos, and of taking to the airwaves to promote Al-Qaeda's war against America after the 9/11 attacks.

According to the indictment, he allegedly threatened Americans, warning them that a "great army is gathering" and "the storms shall not stop, especially the airplanes storm."

The indictment also stated Ghaith was "smuggled successfully from Afghanistan into Iran" in 2002.

Ghaith is one of a number of Al-Qaeda terrorists who were known to be in Iran after the 9/11 attacks but their precise status -- and whether they were placed under house arrest by the Iranian authorities -- has remained unclear.