The Boston Marathon bombers had planned to detonate their remaining explosives in New York City's Times Square, law enforcement officials told US network NBC News.
Dzhokhar Tsarnaev had initially told questioners in hospital that he and his brother were planning to go to New York to "party", but later changed his story to say they wanted to explode more bombs.
One senior official told NBC News that the Tsarnaev brothers' plan was "undeveloped and aspirational at most."
More top news
The NHS is to set up 11 centres to unlock the secrets of DNA and help develop tests and drugs to target cancer and rare genetic diseases.
Australian businessman named as Alan Sugar's newest apprentice and winner of a £250,000 investment in his fledgling company.
The 270 victims of the Lockerbie bombing have been remembered today, 26 years to the day that they lost their lives in the air disaster.