Zarein Ahmedzay, a Queens taxi driver, admitted his role during a hearing in federal court. Najibullah Zazi of Denver earlier pleaded guilty to participating in the alleged plot against the New York subway system. A third defendant, Adis Medunjanin, will stand trial.
The second of three men accused of plotting with Al-Qaeda to carry out a series of rush-hour bomb attacks on New York City subways in September 2009 pleaded guilty on Friday, as prosecutors provided new details about the aborted terror mission.
The action leaves a single defendant, Adis Medunjanin, to stand trial on a five-count indictment.
All three defendants face up to life in prison.
According to federal prosecutors, the three men traveled to Pakistan in August 2008 and met with two Al-Qaeda leaders, Saleh Al-Somali, head of international operations for Al-Qaeda, and Rashid Rauf, described as a key Al-Qaeda operative.
The three Americans told the Al-Qaeda officials they wanted to fight in Afghanistan, but the leaders suggested they would be more useful to Al-Qaeda if they returned to New York to carry out suicide attacks, prosecutors said.