New Canadians will have to remove garments that cover their faces when undergoing an oath of citizenship, Immigration Minister Jason Kenney said Monday.

The minister told a news conference in Montreal that the ban includes the Islamic niqab or burqa. It takes effect immediately.

Kenney said there have been complaints that it is difficult to say whether individuals are actually taking the oath if their faces are covered when doing so.

He also said that new Canadians should be taking the oath in front of fellow citizens.

"This is really a matter of pure principle -- which is at the heart of our public values," Kenney said in French.

"The oath of citizenship is a public gesture."

Kenney said he did not believe that veils are a religious requirement for Muslim women in all circumstances.

"When Muslim women do the hajj to Mecca as part of their Koranic obligation of pilgrimage to the holy sites, they are required not to wear a veil. They are required to show their face," Kenney said in English.

"So the notion that this is somehow a religious obligation, I don't accept."

The ban comes at a time when the Supreme Court is hearing arguments as to whether a Muslim woman has the right to wear her veil when testifying against two men she accuses of sexually assaulting her.

But Nermine Barbouch, a Muslim woman from Montreal, suggested that such a ban contravenes the Charter.

"We can't contradict our own system. Our country gives those women and every Canadian citizen to show up dressed as they wish, especially if it's related to religion," she told CTV Montreal.

Salam Elmenyawi, president of Muslim Congress of Montreal, said that the new rule is disturbing, as well as unnecessary.

He noted that the law is "for a non-existent problem," but he added that the new rule sends the message to Muslims that "they have some kind of a problem" that requires special regulations.

With files from The Canadian Press