Suspended more than 300m above downtown Toronto, six new Canadians took the oath of citizenship on Tuesday from the edge of one of the world's tallest structures.

Canadian Immigration Minister Ahmed Hussen administered the oath to the new citizens, originally from six different countries, as they were held in cables off a 116-story-high platform known as the EdgeWalk, on the side of the landmark CN Tower.

The tower, which reaches 553m, has hosted citizenship ceremonies before, but not one from such breathless heights, according to Immigration, Refugees and Citizenship Canada.

Canada, which prides itself on the country's multiculturalism, accepted more than 270,000 new immigrants in 2017.

"The sky is the limit with #Canadian citizenship," tweeted the minister after the ceremony.