Canada is exploring the use of gender-neutral options on identity cards, Justin Trudeau told a television station on Sunday as he became the first Canadian prime minister to march in a gay pride parade.

Trudeau did not give details, saying only the government was exploring the "best way" and studying other jurisdictions.

"That's part of the great arc of history sweeping towards justice," he told CP24.

A PMO spokeswoman confirmed to CBC News they are looking into changes.

"We are conducting a review of all the circumstances in which the government requires or produces identity documents in order not to exclude people whose gender identity does not match the binary standard. This could include neutrality in several situations," Andrée-Lyne Hallé wrote in an email.

Last week, Ontario said it would allow the use of a third gender indicator, X, for driver's licences.

Countries including Australia, New Zealand and Nepal already allow the use of the X gender indicator.

Trudeau also said last month's relaxation of Canadian blood-donation restrictions on men who have sex with other men was "not good enough," saying the government was going to work toward easing it further.

According to Canadian Blood Services, men who have sex with other men can now donate after one year of abstinence, down from five years previously.