(Reuters) - U.S. Secretary of State Antony Blinken urged India to cooperate with a Canadian investigation into the murder of a Sikh separatist during a meeting with Indian foreign minister Subrahmanyam Jaishankar on Thursday, a U.S. official said.

Speaking in Quebec earlier on Thursday, Canadian Prime Minister Justin Trudeau, who has alleged an Indian role in the killing, said he was certain that Blinken would broach the issue with Jaishankar.

India has dismissed Canada's allegations as absurd, and ties have become strained with both governments expelling a diplomat in a tit-for-tat move.

"Blinken raised the Canadian matter in his meeting, (and) urged the Indian government to cooperate with Canada’s investigation," the U.S. official said, though a State Department statement made no mention of the issue.

Trudeau told parliament earlier this month that Canada suspected Indian government agents were linked to the murder of Hardeep Singh Nijjar in the province of British Columbia in June.

Nijjar was a Canadian citizen but India had declared him a "terrorist." He supported the cause of Khalistan, or an independent homeland for Sikhs to be carved out of India.

Traditional Canadian allies, including the United States, have appeared to take a cautious approach to the matter. Political analysts have said this is partly because Washington and other major players see India as a counterweight to the growing influence of China.

Blinken met Jaishankar on Thursday afternoon in Washington. Asked directly whether Blinken would bring up the case, Trudeau replied: "The Americans will certainly discuss this matter with the Indian government."

The U.S. State Department's formal statement on its website after Blinken met his Indian counterpart made no mention of Nijjar's murder or of Canada as a whole.

A short State Department summary of the issues discussed in the meeting between Blinken and Jaishankar, formally called a readout, listed points like India's G20 presidency, the creation of an India-Middle East-Europe corridor and topics like defense, space and clean energy.

Jaishankar said on Tuesday that New Delhi has told Canada it was open to looking into any "specific" or "relevant" information it provides on the killing.

Trudeau, who is yet to publicly share any evidence, said last week he has shared the "credible allegations" with India "many weeks ago."

Blinken and U.S. national security adviser Jake Sullivan said last week the United States was "deeply concerned" about the allegations raised by Trudeau.

The U.S. ambassador to Canada told Canadian television that some information on the case had been gathered by the Five Eyes intelligence alliance, which includes the U.S., Canada, Australia, New Zealand, the UK.