United States officials have told their Indian counterparts they want a speedy result and more accountability after their investigation into Indian involvement in a foiled murder plot against a Sikh activist in the US, according to an official.

An Indian Inquiry Committee visited Washington last week to discuss India’s own investigations after the Justice Department alleged an Indian intelligence official had directed plans to assassinate dual US-Canada citizen Gurpatwant Singh Pannun, a Sikh separatist, last year.

“We’ve communicated really clearly that the US government isn’t going to feel fully satisfied until we see that meaningful accountability takes place,” said a US official who declined to be named. “We have been emphasising that we hope that India will move as quickly as possible through their investigative process.”

The Indian embassy in Washington did not immediately respond to a request for comment. Washington’s message to Indian officials has not been previously reported.

Last week, an unsealed indictment showed that the United States had charged Vikash Yadav, described as a former officer in India’s Research and Analysis Wing spy service, with directing the plot against a Sikh separatist in New York City.

The indictment alleged that beginning in May 2023, Yadav, described as an employee of the Indian government at the time, worked with others in India and abroad to direct a plot against Pannun.

The accusations have tested Washington’s relations with India, which the Biden administration sees as a potential counterbalance to China’s ambitions in the Indo-Pacific.

“India remains an incredibly important and valuable strategic partner,” the US official said. “We also have to have trust and an ability to work through very difficult issues like this transparently.”

India has labelled Sikh separatists as “terrorists” and threats to its security. Sikh separatists demand an independent homeland known as Khalistan, which would be carved out of India. An insurgency in India during the 1980s and 1990s killed tens of thousands.

Pannun, the Sikh separatist, has alleged that Yadav was a “mid-tier soldier” assigned the task of organising the assassination by higher-level Indian officials.

India has said little publicly since announcing in November 2023 that it would formally investigate the allegations, and it has separately continued a diplomatic dispute with Canada over the June 2023 assassination of another Sikh leader.

Canadian Prime Minister Justin Trudeau said in September 2023 his country’s intelligence agency was pursuing credible allegations that Prime Minister Narendra Modi’s government was behind the killing of Hardeep Singh Nijjar, a Canadian Sikh separatist.

India has denied involvement in both incidents.