Faisal Shahzad, a US citizen, pleaded guilty in June to the May 1 bomb attempt in one of New York’s busiest streets.
Shahzad, 30, was defiant at his last court appearance, claiming to have parked the failed car bomb in revenge for attacks by US drones in Pakistan.
Prosecutors say he should be shown no clemency.
“Far from providing an explanation for his criminal activity, Shahzad’s history and characteristics strongly militate in favor of the maximum available sentence,” assistant US attorney Randall Jackson said in court papers ahead of the sentencing hearing.
The bombing attempt failed when the crude device, left in an SUV parked outside a theater on a warm Saturday evening, fizzled without igniting.
But officials say that the bomb would have caused carnage if it had gone off.
Prosecutors also note that Shahzad boasted he expected to kill at least 40 people and that he planned to set off a second explosion had he not been caught after the first.
According to prosecutors, he admitted using Internet webcam sites to monitor Times Square and see when and where a bomb would be most likely to cause bloodshed.
The car bomb was discovered smoking by a street vendor who alerted police.
Once the teeming area had been cleared, police dismantled the device and launched a frantic manhunt, catching the bomber 53 hours later, just after he boarded a plane preparing to leave from JFK airport to Dubai.
The son of a Pakistani air force officer, Shahzad came to the United States to study at the age of 18 and in 2009 became a naturalized American citizen.
Living in suburban Connecticut, he worked as a financial analyst and married another Pakistani-American, raising two children. But he said in a Taliban video that he became disillusioned with his estrangement from Islam and upset at what he considered humiliation of Muslims worldwide.
The video was apparently shot while Shahzad was receiving training in Taliban-friendly regions in Pakistan over the previous year, before coming back to Connecticut and gathering materials for the bomb. —AFP