Innovation Minister Navdeep Bains says he was asked to remove his turban during what he called an awkward incident at a checkpoint in the Detroit airport a year ago.

Bains described how after one initial encounter with security officials who wanted him to remove his turban, he was allowed to pass -- only to be summoned back from the gate because of a problem with a swab test.

Bains says at no point did he remove his turban, which is mandatory head wear for Sikhs.

While he was eventually allowed to board once he presented a diplomatic passport, he says it should not have mattered that he was a cabinet minister.

He recounted his experience to Foreign Affairs Minister Chrystia Freeland, and she said her officials raised the issue with their American counterparts.

The U-S has since expressed regret and has apologized to Bains.