US warns India as it thwarts plot to kill Sikh separatist leader in America

United States authorities have thwarted a plot to kill a Sikh separatist leader Gurpatwant Singh Pannun in America and issued a warning to India over concerns the right-wing government in New Delhi was involved, a senior Biden administration official said.

The US is treating the plot with utmost seriousness and has raised the issue with the Indian government "at the senior-most levels," the White House said on Wednesday.

US authorities raised concerns with New Delhi that the Indian government may have had knowledge of the plot, according to the official who was not authorised to comment on the sensitive matter.

The official declined to comment on when or how US officials became aware of the plot, as well as how the alleged assassination attempt was derailed.

The FBI is investigating the matter, the official said. Spokespeople for the FBI and Justice Department declined to comment Wednesday.

The thwarted assassination plot was first reported by the Financial Times, which said the US informed some allies of the alleged plot.

The FT said its sources did not say if the US protest to India resulted in the plot being abandoned, or if it was foiled by the FBI. It said the protest was registered after Indian Prime Minister Narendra Modi was welcomed on a state visit by President Joe Biden in June.

Apart from the diplomatic warning to India, US federal prosecutors have also filed a sealed indictment against at least one suspect in a New York district court, the FT said.

The official who spoke to AP news agency added that US authorities had raised concerns over the plot at the highest levels of the Indian government, and officials in New Delhi indicated they were treating the matter seriously.

"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. Indian counterparts expressed surprise and concern," National Security Council spokesperson Adrienne Watson said in a statement.

"They stated that activity of this nature was not their policy. Based on a discussion with senior US government officials, we understand the Indian government is further investigating this issue and will have more to say about it in the coming days.

We have conveyed our expectation that anyone deemed responsible should be held accountable," the statement added.

The issue is a highly delicate one for the Biden administration, which has been working to develop close relations with India given shared concerns about China's rising power.

Sikh activist's murder in Canada

Law enforcement officials have repeatedly warned about what they say is an alarming trend of foreign governments seeking to harass, stalk or intimidate dissidents and political opponents in the US.

India's Foreign Ministry issued a statement noting that the US had raised information pertaining to a "nexus between organised criminals, gun runners, terrorists and others" during recent conversations.

The statement described the information as a "cause of concern for both countries" and said India takes it seriously.

The revelation follows the September disclosure by Canadian Prime Minister Justin Trudeau of what he said were credible allegations that the Indian government may have had links to the assassination in that country of Sikh activist Hardeep Singh Nijjar.

India rejected the accusation as absurd, but Canada expelled a top Indian diplomat while it investigated.

Nijjar supported creating a Sikh homeland in the form of an independent, so-called state of Khalistan in India's northern state of Punjab, the birthplace of the Sikh religion, which borders Pakistan.