The Associated Press says U.S. Secretary of State John Kerry will sign the Arms Trade Treaty on Wednesday during the United Nations General Assembly.
The NDP sent Foreign Affairs Minister John Baird a letter this past week asking that Canada join 85 countries and sign the treaty, but has received no reply.
Canada initially supported the treaty, but earlier this spring Baird suggested the government would require further study before deciding whether to adopt it.
Baird has said there is a potential link between signing on to the treaty and Canada's now-abolished long gun registry.
Amnesty International says if the U.S. signs the treaty it would mark a milestone towards curbing the flow of weapons and the atrocities they fuel.
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