His lawyer had no comment on the new charge "at this time." Zazi had been arrested initially on a charge of lying to FBI agents in Denver.
The language in the court documents suggests many others were involved with Zazi in what is shaping up as the most serious attempt by al Qaeda to strike at the United States since the Sept. 11 attacks.
Authorities say when Zazi traveled to New York on Sept. 10, he stayed in an apartment in Queens where agents later found a small scale that "contained Zazi's fingerprints" and would "be suitable for performing several of the procedures outlined" in the al Qaeda bomb making instructions.
Zazi appeared in court in Denver today, and is scheduled to make another appearance Friday.
ABC News' Angela Hill, Rehab El-Buri and Joseph Rhee contributed to this report.