First of all, I think it would be a fairly long negotiation to deepen their GPA commitments, because it would involve obligations being taken by states and municipalities. Secondly, although I don't have an expertise in American legislative procedure, I believe they would require congressional approval to expand their coverage. But I know for sure, because we have looked at the question, that they would not require any congressional approval to take on their existing level of obligations in the GPA with a new member, Canada.
On October 6th, 2009. See this statement in context.