The issue comes at a delicate time for both India and the Biden administration as they try to build closer ties in the face of an ascendant China perceived as a threat for both democracies.
Just a week before the foreign ministry's statement on Wednesday, the White House confirmed it had warned New Delhi about its involvement in a thwarted plot to kill a Sikh separatist leader, Gurpatwant Singh Pannun.
"India takes such inputs seriously since they impinge on our national security interests as well," the ministry said, vowing to "take necessary follow-up action" on the findings of the panel set up on November 18.
The Financial Times newspaper on November 22 first reported the thwarted plot against Pannun in the United States.
The White House said it was treating the issue with "utmost seriousness" and had raised it with India at the "senior-most levels".
The foiled plot and the US concerns were reported two months after Canada said it was looking at credible allegations linking Indian agents to the June murder of Hardeep Singh Nijjar, another Sikh separatist, in a Vancouver suburb.
New Delhi fiercely rejected Ottawa's accusations, and has said it is yet to provide any "specific or relevant" information for India to look into.
The US had started voicing its concerns and related details to Prime Minister Narendra Modi's government as early as April, an Indian official who is aware of the matter, but not authorised to speak to the media, told Reuters.
The official said the issue was also discussed on November 10, when Secretary of State Antony Blinken and Defence Secretary Lloyd Austin met their counterparts in the Indian capital for the so-called 2+2 dialogue.
Those talks focused on defence co-operation and security concerns in the Indo-Pacific region.
Like the murdered Canadian, Pannun, the target of the thwarted plot in the US, is a proponent of a decades-long demand to carve out an independent Sikh homeland from India called Khalistan that sparked a violent insurgency in the 1970s and 1980s.
Although now relegated to the fringes of politics, the demand continues to be viewed with concern by New Delhi.
