Faisal Shahzad, son of a retired Pakistani Air Vice Marshal, has admitted to attending a terrorist training camp in restive Waziristan before his failed bid to explode a car bomb at the Times Square in New York.
30-year-old Shahzad, a naturalised American citizen, would be charged with an act of terrorism, even as seven people were detained in Pakistan for alleged links to him.
A day after arresting him from the New York's John F Kennedy Airport when he was trying to flee the country, the Federal Bureau of Investigation (FBI) said Shahzad confessed he had attempted to detonate a bomb at Times Square.
Shahzad also told the FBI that he received bomb-making training at a terror camp in Waziristan, a lawless tribal region where the Pakistani Taliban and other militant groups operate with near impunity.
Pakistani chief military spokesman Maj Gen Athar Abbas said in Islamabad that Shahzad comes from a "well to-do" family and that his father was a former air force officer.
Asked about the claims by Pakistani Taliban that it was behind the failed plot, Abbas said "anybody can claim anything. But one has to see the reach, the capability of the organisation and whether it is capable of conducting such kinds of acts so far away in another country."
He said none of the agencies have so far confirmed any arrests though many people have been questioned in this connection.
Shahzad's training in Waziristan raised the possibility of a coordinated international plot for an attack.
In a 10-page complaint filed yesterday before the Court of Judge Nathaniel Fox, Southern District of New York, the FBI alleged Shahzad travelled from Connecticut to New York on a sports-utility vehicle (SUV) that was laden with a bomb.
US Attorney General Eric Holder said Shahzad would be charged with an act of terrorism and that he is cooperating with investigators and providing useful details.
He would be charged with an act of terrorism transcending national borders, attempted use of a weapon of mass destruction, use of a destructive device during the commission of another crime, as well as assorted explosives charges, he said.
"After the arrest Shahzad admitted that he had attempted to detonate a bomb in Times Square. He also admitted that he had recently received bomb-making training in Waziristan, Pakistan," the FBI said.
Meanwhile, authorities in Pakistan detained seven men from different parts of the country for their alleged links with Shahzad.