UNITED NATIONS - Canada demanded a tougher international response yesterday to countries that block humanitarian aid, telling the UN Security Council they should be punished.

Describing the situation in Burma as a "matter of life and death," John McNee, the Canadian ambassador to the UN, said the body has the power under international law to act, but getting help to where it's needed "remains an elusive goal."

"Those who refuse access cannot be allowed to act with impunity," he said. "Enhanced accountability, underscored by a clear demonstration by the council that systematic denial of access will not be tolerated, is more important than ever."

Mr. McNee spoke at an "open" security council debate on the protection of civilians in armed conflict.

Canada's stance serves as a challenge not only to the council's 15 members, but also to itself should Ottawa win a seat on the UN's most powerful body in coming years. States such as Burma get away with defying the security council principally because China and Russia, two of the five permanent members with veto power, traditionally oppose UN-ordered intervention without the consent of the target state.

It was not clear what Canada would do to persuade offending countries to change their ways, other than emphasizing the immorality of letting people die. "Member states have a collective interest in ensuring safe and unhindered humanitarian access to civilians in need," Mr. McNee said.

"This is not simply an aspirational statement; it is a fundamental principle of international humanitarian action."