Jose Pimentel, 27, was charged with three terrorism-related counts and two other counts, court documents said.

A US citizen born in the Dominican Republic, Pimentel was arrested on November 19 in a Manhattan apartment while putting the bomb together, police said. They called him a "lone wolf" who had converted to Islam and became a radical.

In an interview with New York police, Pimentel admitted he "took active steps to build the bomb, including shaving the match heads and drilling holes in the pipes" and was "one hour away from completing it," said the criminal complaint filed by the Manhattan District Attorney.

Pimentel, who has not been charged federally, faces life in prison if convicted.

He was under surveillance since May 2009 and considered New York police cars, a New Jersey police station and US post office among his potential targets, officials said.

As a reader of the online magazine "Inspire" published by al Qaeda in the Arabian Peninsula, Pimentel took instructions from an article "How to Build a Bomb in the Kitchen of Your Mom," Police Commissioner Ray Kelly told a news conference.