Security personnel stand guard in front of the High Commission of Canada in New Delhi
AFP

Canadian Prime Minister Justin Trudeau on Thursday called on India to cooperate with its investigation into the murder of a Sikh separatist after earlier this week pointing to Indian agents as suspects.

"We call upon the government of India to work with us to establish processes to uncover the truth of this matter and to allow for justice and accountability to be served," Trudeau said on the sidelines of the United Nations General Assembly in New York.

He declined, however, to provide the evidence that led him on Monday to accuse India in the slaying, suggesting that would be left for courts to make public should the case ever go to trial.

On Monday, Trudeau triggered a major diplomatic row when he raised allegations that Indian agents played a role in the June murder of Hardeep Singh Nijjar, a Canadian citizen, near Vancouver.

The fallout prompted tit-for-tat diplomatic expulsions and a forceful denial from India, which said any suggestion it played a role in Nijjar's killing was "absurd."

India also stopped handling visa applications in Canada, blaming "security threats" which they said were "disrupting" the work of their officials, and sought a reduction of Canadian diplomatic staff in India.

Trudeau insisted on Thursday that his government "is not looking to provoke or cause problems" when asked why Canada's allies' reactions to the allegations appeared muted.

Western powers led by the United States have been courting India for years, seeing a natural ally in the billion-plus democracy as concerns mount about China.

"There is no question that India is a country of growing importance, and a country that we need to continue to work with," Trudeau said.

"But we are unequivocal around the importance of the rule of law and unequivocal about the importance of protecting Canadians."