WASHINGTON, March 8 (RIA Novosti) - Osama bin Laden’s son-in-law, a man prosecutors say worked alongside the 9/11 mastermind in a “campaign of terror,” pleaded not guilty in a New York City federal courtroom on Friday, only blocks from the site of the 9/11 terror attack, to a charge of conspiracy to kill Americans.

Sulaiman Abu Ghaith “urged others to swear allegiance to bin Laden, spoke on behalf of and in support of al-Qaeda’s mission, and warned that attacks similar to those of September 11, 2001 would continue,” according to the indictment unsealed in federal court on Thursday.

Handcuffed when he entered the courtroom under tight security and dressed in blue, prison-issued clothing with a gray beard, Abu Ghaith nodded “yes” when asked through an interpreter if he understood his rights, but otherwise spoke very little at Friday’s hearing.

His attorney, Philip Weinstein, entered a plea of “not guilty” on his behalf.

US prosecutors say Abu Ghaith held a “key position” in the al-Qaeda network, which was “comparable to the consigliere in a mob family.”

Among the specific acts he is accused of: urging people at a guest house in Afghanistan to take an “oath of allegiance” to bin Laden; agreeing to help bin Laden before the 9/11 attacks; issuing a statement the day after the attacks that called upon the “nation of Islam” to battle “the Jews, the Christians and the Americans;” warning the United States after 9/11 that the “airplane storm” would not stop and urging Muslims and children to avoid airplanes and high rise buildings.

Abu Ghaith, who once was a spokesman for al-Qaeda, is married to bin Laden’s daughter, Fatima.

“He used his position to persuade others to swear loyalty to al-Qaeda’s murderous cause. He used his position to threaten the United States and incite its enemies. His apprehension is another important step in the campaign to limit the reach of al-Qaeda and enhance our national and international security,” said FBI Assistant Director-in-Charge George Venizelos in a statement released by the US Department of Justice.

Abu Ghaith was taken into US custody in Jordan last month and flown to the United States on March 1.

The decision by the US government to hold Abu Ghaith’s trial in New York has angered some Republican lawmakers, who say it provides him with a public platform and greater privileges than he would get with a military tribunal at the US naval prison at Guantanamo Bay, Cuba.

“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 civilian court,” said Sen. Kelly Ayotte, a member of the Homeland Security and Governmental Affairs Committee.

"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 US court system is not the appropriate venue," said Rep. Mike Rogers, chairman of the House Intelligence Committee.

Abu Ghaith’s attorney did not ask for him to be released on bail in court on Friday. The judge ordered him to appear in court again April 8.