Faisal Shahzad was on a Dubai-bound plane at JFK airport on Monday that was turned back as it taxied for take-off.
According to court papers, Mr Shahzad has admitted his role in Saturday's attempted attack and said he received training in bomb-making in Pakistan.
The Pakistan-born US citizen has been charged with terrorism-related crimes.
These include attempting to use a weapon of mass destruction and transporting an explosive device with the intent to kill.
"It is clear that this was a terrorist plot aimed at murdering Americans in one of the busiest places in the country," said Attorney General Eric Holder.
Mr Shahzad did not appear before a judge on Tuesday as expected to hear the charges. No reason has been given for the delay.
He is alleged to have bought an SUV that was found loaded with an improvised bomb in Times Square.
The unexploded bomb left crucial evidence intact that detectives used to trace Mr Shahzad, including the vehicle's identity number.
With that number, police found the former owner who said she sold it to Mr Shahzad for cash without official paperwork being exchanged.
But the former owner had Mr Shahzad's mobile phone number and gave it to police.
The pre-paid phone had also been used to call a Pennsylvania fireworks shop, the court documents said.
Despite his name being added to the government's no-fly list earlier on Monday, Mr Shahzad managed to buy a ticket on an Emirates flight to Dubai and made it through JFK's security checks late that evening.
He booked the ticket while on his way to the airport and paid for it with cash, police said.
Customs agents checking the passenger list about 30 minutes before the plane was due to take-off realised Mr Shahzad's name was on it and stopped the flight with just minutes to spare as it taxied to the runway.
Despite the suspect nearly managing to leave the country, Mr Holder denied he would have escaped.
"I was never in any fear that we were in danger of losing him," he said.
Alarm raised
The car containing a bomb made from fertiliser, fireworks, petrol and propane gas tanks was left in Times Square on Saturday evening.
The 1993 Nissan Pathfinder was parked with its engine running and hazard lights flashing.
The bomb was discovered and dismantled before it could explode, after a street-vendor noticed smoke coming from the vehicle and alerted police.
Times Square was packed with tourists and theatregoers when the alarm was raised.
Police evacuated a wide area of the district and closed subway lines, while a controlled explosion was carried out.
Officials said the bomb was crude, but could have sparked a "significant fireball" and sprayed shrapnel with enough force to kill pedestrians and knock out windows.
Investigators said the Connecticut resident implicated himself and told them he was acting alone.
But court documents stated that he admitted having attended a militant training camp in the lawless Pakistani tribal region of Waziristan.
He apparently told investigators the plot had begun in December last year.
Pakistani authorities have reportedly arrested two men associated with Mr Shahzad and US investigators are looking at possible links to foreign militant groups.
