A US citizen accused of traveling to Pakistan to train with al Qaeda pleaded not guilty to terrorism charges in federal court in New York on Thursday.

Texas-born Muhanad Mahmoud Al Farekh spoke only briefly during a short court appearance in Brooklyn, confirming to a US judge that he understood the indictment against him and his rights.

Prosecutors said Farekh was at least partially radicalized by the online sermons of Anwar al-Awlaki, the US-born militant preacher associated with al Qaeda in the Arabian Peninsula who was killed in Yemen in a 2011 US drone strike.

That was the first instance in which the United States targeted and killed an American citizen with a strike, prompting criticism from civil liberties advocates that the act was unlawful.

Farekh studied at the University of Manitoba in Winnipeg, Canada, according to prosecutors. Around 2007, he and two other students, Ferid Imam and an unnamed person, decided to travel to remote tribal areas along Pakistan's border with Afghanistan and train with al Qaeda, US authorities said.

Imam also provided training at an al Qaeda camp in Pakistan in September 2008 to Najibullah Zazi and two other men later convicted of plotting a suicide bombing attack in the New York City subway system, according to the US Justice Department.

Imam's whereabouts are unknown.

The criminal complaint against Farekh said that two cooperating witnesses in his case were also involved in the subway plot.

Farekh faces charges of providing material support to terrorists as well as attempting and conspiring to provide such support. He faces up to life in prison if convicted.