Indian Prime Minister Narendra Modi conveyed strong concerns about protests in Canada against India to Canadian Prime Minister Justin Trudeau on the sidelines of the G20 summit in New Delhi, according a statement by India.

New Delhi has been long sensitive to Sikh protesters in Canada. In June, India criticized Canada for allowing a float in a parade depicting the 1984 assassination of Indian Prime Minister Indira Gandhi by her bodyguards, perceived to be glorification of violence by Sikh separatists.

"They are promoting secessionism and inciting violence against Indian diplomats, damaging diplomatic premises and threatening the Indian community in Canada and their places of worship," the Indian statement said.

Relations between India and Canada remain tense, and Ottawa this month paused talks on a proposed trade treaty with India, just three months after the two nations said they aimed to seal an initial agreement this year. Modi, who held bilateral meetings with many world leaders during the G20 summit, did not hold one with Trudeau.

Indira Gandhi was assassinated in 1984 by two Sikh bodyguards after she allowed the storming of the holiest Sikh temple in northern India, aiming to flush out Sikh separatists who demanded an independent homeland to be known as Khalistan.

Canada has the highest population of Sikhs outside their home state of Punjab in India, and the country has been the site of many protests that have irked India.

Canada will always defend "freedom of expression, freedom of conscience and peaceful protest," Trudeau said at a press conference in New Delhi.

"At the same time as we are always there to prevent violence, to push back against hatred," he said, adding that the actions of the few "do not represent the entire community or Canada."

Trudeau's departure from the G20 summit was delayed on Sunday by a technical problem with the Canadian delegation's aircraft, a statement from the prime minister's office said. The delegation will stay in India until alternate arrangements are made, it added.