Mark Toner, a spokesperson for the US State Department, also emphasised the need for India and Pakistan to work together to defeat terrorists, reported Dawn online.
"We want to see better, stronger, closer counter-terrorism cooperation not only between the US and India but of all the countries in the region, including Pakistan," said Mark Toner.
"We all need to be on our guard. We all need to be vigilant. We all need to cooperate and share information and intelligence where we can to prevent future attacks," he said.
"Perpetrators of the 2008 Mumbai terror attack, that left 166 people dead, to be brought to justice," said he.
"We continue to follow the criminal proceedings closely, and urge additional actions to prevent such an attack from ever happening again. And recognise that this was a terrible tragedy for India," Toner said.