By Jessica Dye

NEW YORK (Reuters) - A Bangladeshi man is expected to plead guilty Thursday to attempting to blow up the New York Federal Reserve Bank with what he believed to be a van packed with explosives, according to court documents.

Quazi Mohammad Rezwanul Ahsan Nafis, 21, was arrested on October 17 after pulling up to the Federal Reserve and attempting to detonate what he believed to be a 1,000-lb (454-kg) bomb hidden in a van.

In fact, an undercover agent provided the explosives to Nafis as part of a sting operation, and the bomb was never in working condition, federal authorities said.

Nafis was charged with one count of attempting to use a weapon of mass destruction and one count of attempting to provide material support to a U.S.-designated foreign terrorist organization, al Qaeda. He faced up to life in prison on those charges.

Nafis' attorney could not be reach after the close of business for comment.

According to a criminal complaint unsealed in October, Nafis entered the United States in 2012 with a student visa, and eventually traveled to Queens, New York.

There, he scouted out targets for a potential attack - including the New York Stock Exchange and U.S. President Barack Obama - settling eventually on the Federal Reserve Bank in Manhattan, the complaint said.

Nafis attempted to recruit others to his plot, and discussed his plans over social media sites such as Facebook, the complaint said. He claimed he was in contact with al Qaeda operatives overseas, and actively sought out new al Qaeda connections in the United States, the complaint said.

One of the individuals he brought onboard was an undercover agent working for the FBI, who monitored Nafis' activities and helped arm him with the inoperable explosives, federal authorities said.

From Bangladesh, the suspect's father has denied his son was involved and said he was the victim of a "racist conspiracy."

(Reporting by Jessica Dye; Editing by Lisa Shumaker)