A top United States official on Wednesday asked India to cooperate with investigation into allegations made by Canadian Prime Minister Justin Trudeau that New Delhi may have been involved in the assassination of a Sikh separatist leader in suburban Vancouver.

White House national security spokesman John Kirby told CNN that US President Joe Biden was “mindful of these serious allegations” and the country supported Canada’s efforts to investigate the matter.

“We believe a fully transparent comprehensive investigation is the right approach so that we can all know exactly what happened and of course, we encourage India to cooperate with that,” Kirby said.

On Monday, Trudeau told Parliament that Canadian intelligence agencies were actively pursuing “credible allegations” tying Indian agents to the shooting of Hardeep Singh Nijjar, a 45-year-old Sikh leader who was killed by masked gunmen on June 18 in Surrey, outside Vancouver.

India has rejected the charges as “absurd and motivated”. It also expelled a Canadian diplomat, in a tit-for-tat move after Canada expelled an official of the Indian foreign intelligence service.

Trudeau’s accusations marked a significant escalation in tensions between Canada and India, both G20 members.

Canada is also part of the Five Eyes intelligence sharing alliance with the United States, the United Kingdom, Australia and New Zealand. On Wednesday, when asked what information Trudeau had shared with Biden about the killing of Nijjar, Kirby said he wanted to respect the sanctity of the investigation.

When questioned about possible repercussions of the allegations, Kirby said, “Let’s not get ahead of where we are. There’s an active investigation. We think it needs to be fully transparent, comprehensive. We know that Canadians will work to that end”.

He told CBS News that the US will stay in touch with India and Canada about this issue.

US Ambassador to India Eric Garcetti also said on Wednesday that those who are responsible for the murder must be held accountable and there should be a space for investigation before a judgement is made.

“We hope that traditional friends and partners will cooperate in getting to the bottom of it,” he said.

The envoy underlined the importance of following principles of international law, sovereignty and non-interference. “We are in close communication with Canada,” he added. “Canada is a dear friend, ally, partner and neighbour.”

Canada has not yet made public the intelligence it has regarding India’s alleged involvement in Nijjar’s death.

The Washington Post reported that Trudeau had pushed for a joint statement condemning India at last week’s Group of 20 summit in New Delhi but was turned down by the United States and other allies. White House National Security Council spokesperson Adrienne Watson, however, said that such reports are “flatly false”.

The accusations have put the US, Britain and Australia in an uncomfortable position since the three countries have sought to bolster ties with India in recent years.

Britain has said it was important for the Canadian investigation to run its course to determine whether India was involved in the killing of Nijjar while Australia said the revelations were “deeply concerning”.

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