The Pakistani Taliban chief Hakimullah Mehsud had met Pakistani-American Faisal Shahzad who tried to bomb New York's Times Square, shows a new video footage.
The video clip shows Shahzad and Mehsud shaking hands and hugging each other sometime before the failed May 1 attack, Sky News reported on Friday.
Shahzad can be heard saying: "Today, along with the leader of Tehrik-e-Taliban Pakistan Hakimullah Mehsud and under the command of Amir al-Mumineen Mullah Mohammed Omar Mujahid (may Allah protect him), we are planning to wage an attack on your side, inshallah."
A federal grand jury last month indicted Shahzad in the Times Square bombing attempt on 10 counts, including attempt to commit international terrorism and use a weapon of mass destruction.
Six of the charges against Shahzad, 30, carry a maximum life sentence if convicted, including two that bring a mandatory life sentence, according to a Department of Justice statement issued after his indictment.
"The facts alleged in this indictment show that the Pakistani Taliban facilitated Faisal Shahzad's attempted attack on American soil," said Attorney General Eric Holder.
Shahzad received explosives training and money from people believed to be associated with Tehrik-e-Taliban, a militant extremist group in Pakistan, according to the indictment and a previous criminal complaint.
Shahzad, a Pakistan-born naturalised American citizen, is accused of attempting to set off the botched vehicle bomb in Times Square.
He was arrested two days later while trying to flee to Pakistan on a flight from New York's John F Kennedy International Airport.