According to the media report the fear was expressed to Admiral Mike Mullen, the top US military commander, during his meetings in New Delhi.
It also claimed that LeT, the terror group behind the 26/11 attacks on Mumbai, has joined forces with the Taliban in a new alliance to kill western soldiers in Afghanistan.
Even American officials are concerned that LeT has expanded its focus to Afghanistan and now has a more global agenda.
“Since 2008 I"ve watched them grow to a terrorist organisation with global aspirations," Mullen said. “It"s an organisation which is becoming more lethal, it"s in Afghanistan and it"s in other countries."
The LeT enjoys widespread support in Pakistan through its charitable arm, which was highly visible after the Pakistan earthquake in 2005 and is now helping to rebuild the Swat valley after a Pakistani offensive against the Taliban.