The National Post reports in its Tuesday edition that Canada's ambassador to the United States, Mark Wiseman, said on Sunday there was no one issue that led talks to the collapse of trade talks late Friday. A Bloomberg dispatch to the Post reports that Mr. Wiseman said after a close look, Canadian negotiators realized that their understanding of what was agreed upon differed greatly from the documents. It's not clear when negotiations might resume, but Mr. Wiseman said the timeline is not about creating an overtime period for talks. Talks stalled due to a dispute over tariffs on medium and heavy vehicles, with the U.S. resisting cuts. Mr. Wiseman noted that Canada required tariff relief for these vehicles, impacting U.S. automakers GM and Ford operating in Canada. "That's just something we could not accept because we want to protect the existence of an automotive assembly industry in Canada for cars, light trucks, you know, medium trucks and heavy-duty trucks." But he added: "This is not why the deal fell apart. That is a very specific example of one of a number of things where, you know, as the interpretation of the details became clear, it became obvious that there wasn't going to be a meeting of the minds."