What you need to know about the conflict between Canada and India 6:22
(CNN) -- Intelligence obtained by the "Five Eyes" network led Canada to make the public accusation that the Indian government may have played a role in the killing of a Sikh separatist activist on Canadian soil, the U.S. ambassador to Canada said Sunday.
I'm "confirming that there was intelligence shared among Five Eyes partners that helped Canada make the statements that the prime minister did," U.S. Ambassador to Canada David Cohen told CTV's quiz show Vassy Kapelos in an interview Sunday.
Five Eyes is an intelligence-sharing pact between the United States, the United Kingdom, Canada, Australia and New Zealand, although the ambassador would not confirm whether that shared intelligence came from the United States. "I wouldn't. I wouldn't do it under any circumstances," Cohen said.
Relations between India and Canada plummeted last week after Canadian Prime Minister Justin Trudeau said authorities had been investigating "credible allegations" that New Delhi was potentially behind the June murder of Hardeep Singh Nijjar, a Sikh separatist activist, who was shot dead by two masked men in Surrey. British Columbia.
India has vehemently denied the claims, calling them "absurd and motivated." Indian External Affairs Ministry spokesman Arindam Bagchi said Canada has not provided "any specific information" to back up the allegations.
Both countries expelled high-level diplomats in reciprocal measures, raising the prospect of an uneasy rift between key U.S. partners.
The dispute escalated further last week when India suspended visa services for Canadian citizens over what it said were "security threats" against diplomats in Canada.
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Speaking to CTV, Cohen said the United States expressed concern to India over the allegations and asked New Delhi to cooperate with Canada in its investigation.
"If they turn out to be true, it is potentially a very serious violation of the rules-based international order," the ambassador said.
On Sunday, Canadian Defense Minister Bill Blair sought to shift the focus from questions about his country's intelligence to the criminal investigation into Nijjar's murder.
In an interview with CBC, Blair said the Five Eyes association is "critically important" and that Canada has "very credible intelligence that concerns us deeply," but declined to identify the sources of that information.
"It's another reason why I put so much emphasis on the investigation that's going on, that we could go beyond credible intelligence to evidence, solid evidence, of exactly what happened, so that we and the Indian government can really know the situation, have the facts and then work together to resolve it properly." Said.
Trudeau on Thursday urged India to "divest itself of full transparency and ensure accountability and justice in this way."
"We call on the government of India to work with us. Take these allegations seriously and allow justice to take its course," the prime minister said at Canada's Mission to the United Nations.
Trudeau said Canada does not seek to provoke or cause trouble, but said its justice system "and robust processes will run its course" regarding the investigation of the allegation.
In a strongly worded statement to reporters Thursday, Bagchi called Canada a "safe haven for terrorists" and that Canada needed to "worry about its international reputation" in the wake of its explosive allegations.
Bagchi said the suspension of visa services for Canadian citizens was due to "incitement to violence" and "inaction" by Canadian authorities.
"Creating an environment that disrupts the functioning of our high commission and consulates, that's what makes us temporarily halt issuing visas or providing visa services," Bagchi said.
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Militancy or campaign?
The Indian government has long accused Canada of inaction in addressing what it said is Sikh separatist extremism aimed at creating a separate Sikh homeland that would be known as Khalistan and include parts of the Indian state of Punjab.
Nijjar was a strong supporter of the creation of Khalistan. India views the calls for Khalistan as a serious threat to national security.
Several groups associated with Khalistan's idea are listed as "terrorist organizations" under India's Unlawful Activities (Prevention) Act (UAPA). Nijjar's name appears on the UAPA's terrorist list and in 2020 India's National Investigation Agency accused him of "trying to radicalize the Sikh community worldwide in favor of the creation of 'Khalistan.'"
Several Sikh organizations abroad say the Indian government is falsely equating this movement with terrorism, and say they will continue to peacefully advocate for the creation of Khalistan, while exposing what they say are years of human rights abuses facing the community in India.
According to local police, Nijjar was shot dead in his truck in June by two masked killers outside a Sikh temple in western Canada.
His death shocked and outraged both Canada's Sikh community, one of the largest outside India and home to more than 770,000 members of the religious minority.
Canadian police have not arrested anyone in connection with Nijjar's murder. But in an August update, the issued a statement saying they were investigating three suspects and issued a description of a possible getaway vehicle, asking for the public's help.
-- CNN's Manveena Suri contributed reporting.