Sikh separatist on American soil with «utmost seriousness» and has raised the issue with New Delhi, the White House said Wednesday.
The Financial Times reported that same day that US authorities had thwarted a conspiracy to kill Gurpatwant Singh Pannun, a US and Canadian citizen.
The row comes two months after neighboring Canada publicly linked Indian intelligence to the killing of another Sikh separatist.
«We are treating this issue with utmost seriousness, and it has been raised by the US government with the Indian government, including at the senior-most levels,» US National Security Council spokeswoman Adrienne Watson said in a statement.
«Indian counterparts expressed surprise and concern.