A Bangladeshi man who came to the United States to wage jihad was arrested in an elaborate FBI sting on Wednesday after attempting to blow up a fake car bomb outside the Federal Reserve building in Manhattan, authorities said.

Before trying to carry out the alleged terrorism plot, Quazi Mohammad Rezwanul Ahsan Nafis went to a warehouse to help assemble a 1,000-pound bomb using inert material, according to a criminal complaint. He also asked an undercover agent to videotape him saying, "We will not stop until we attain victory or martyrdom," the complaint said.

Agents grabbed the 21-year-old Nafis — armed with a cellphone he believed was rigged as a detonator — after he made several attempts to blow up the bomb inside a vehicle parked next to the Federal Reserve, the complaint said.

Plot never posed actual risk

Authorities emphasized that the plot never posed an actual risk. However, they claimed the case demonstrated the value of using sting operations to neutralize young extremists eager to harm Americans.

"Attempting to destroy a landmark building and kill or maim untold numbers of innocent bystanders is about as serious as the imagination can conjure," said Mary Galligan, acting head of the FBI's New York office. "The defendant faces appropriately severe consequences."

Quazi Mohammad Rezwanul Ahsan Nafis, left, was arraigned in the United States District Court of the Eastern District of New York. (Jane Rosenberg/Reuters)

Nafis appeared in federal court in Brooklyn to face charges of attempting to use a weapon of mass destruction and attempting to provide material support to al-Qaeda. Wearing a brown T-shirt and black jeans, he was ordered held without bail and did not enter a plea. His defense attorney had no comment outside court.

The defendant had sought assurances from an undercover agent posing as an al-Qaeda contact that the terrorist group would support the operation.

"The thing that I want to do, ask you about, is that, the thing I'm doing, it's under al-Qaeda?" he was recorded saying during a meeting in bugged hotel room in Queens, according to the complaint.

In a September meeting in the same hotel room, Nafis "confirmed he was ready to kill himself during the course of the attack, but indicated he wanted to return to Bangladesh to see his family one last time to set his affairs in order," the complaint said.

But there was no allegation that Nafis actually received training or direction from the terrorist group.

Prosecutors say Nafis travelled to the U.S. on a student visa in January to carry out an attack. In July, he contacted a confidential informant, telling him he wanted to form a terror cell, the criminal complaint said.

In further conversations, authorities said Nafis proposed several spots for his attack, including the New York Stock Exchange — and that in a written letter taking responsibility for the Federal Reserve job he was about to carry out, he said he wanted to "destroy America." Other communications took place through Facebook, the complaint said.

A Twitter account with the suspect's name and photo had six followers and two messages and was linked to a Facebook page that had been taken down.

Nafis attended Southeast Missouri State University during the spring semester, which ran from January to May, university spokeswoman Ann Hayes told the Southeast Missourian newspaper. He was pursuing a bachelor's degree in cybersecurity.

Hayes said Nafis requested a transfer of his records in July and the university complied, though she couldn't say where the records were transferred.

On Wednesday, federal officials were at the New York home where Nafis was staying, a red brick building in the Jamaica neighborhood of Queens. Owner Rafiqul Islam said Nafis was staying with his second-floor tenants, and he was told he was related to the family. The tenants didn't answer their door and their apartment was dark.

The Federal Reserve building in Manhattan, just blocks from the World Trade Center site, is heavily fortified. (Frank Franklin II/Associated Press)

Islam said Nafis had only lived there about a month or so.

"I didn't notice anything, he spoke to me very quietly," he said. "He said he was going to be studying here."

Police Commissioner Raymond Kelly said the case is one more reminder that New York remains a target: "New York continues to be very much in the mind frame of terrorism. This individual came here with the express purpose of committing a terrorist attack; he was motivated by al-Qaeda. We see this threat as being with us for a long time to come."

Kelly said security is always a precaution and there are about a thousand officers in the counterterrorism division. He didn't specify if any additional measures were being taken.

The bank, located at 33 Liberty St., is one of 12 branches around the country that, along with the Board of Governors in Washington, make up the Federal Reserve System that serves as the central bank of the United States. It sets interest rates.

Federal Reserve building heavily fortified

The Federal Reserve is one of the most fortified buildings in the city, smack in the middle of a massive security effort headed by the New York Police Department where a network of thousands of private and police cameras watch for suspicious activity.

The department uses sophisticated programs that can search for suspicious activity, like an object in one place for a long time, at the building modeled after London's "ring of steel." The analytic software also is designed to take video and catalog it according to movements, shapes and colors, so officers can set parameters to search the system for, say, a suspicious van.

The Fed is also home to the world's largest accumulation of gold, according to the bank's website. Dozens of governments and central banks store a portion of their gold reserves in high-security vaults deep beneath the building. In recent years, it held 216 million troy ounces of gold, or more than a fifth of all global monetary gold reserves, making it a bigger bullion depository than Fort Knox.

The federal case was the latest where a terrorism plot against the city turned out to be a sting operation.

Four men were convicted in 2009 in a plot to bomb synagogues and shoot down military planes with missiles - a case that began after an FBI informant was assigned to infiltrate a mosque in Newburgh, about 70 miles north of New York City. The federal judge hearing the case said she was not proud of the government's role in nurturing the plot.

In 2004, a Pakistani immigrant was arrested and convicted for a scheme to blow up the subway station at Herald Square in Midtown. His lawyers argued that their client had been set up by a police informant who showed him pictures of Iraq abuse to get him involved in an attack against civilians.