The U.S. is "deeply concerned" over accusations by Canadian Prime Minister Justin Trudeau linking Indian government agents to the murder of a Sikh separatist leader in British Columbia in June, the White House said on Monday.

"We are deeply concerned about the allegations referenced by Prime Minister Trudeau earlier today," White House National Security Council spokesperson Adrienne Watson said in a statement.

"We remain in regular contact with our Canadian partners. It is critical that Canada’s investigation proceed and the perpetrators be brought to justice,” the statement said. (Reporting by Eric Beech and Dan Whitcomb)