During that time, Greer helped to see through a trade deal between the United States, Mexico and Canada – although Trump has since announced, and then paused, fresh tariffs on both partners as talks continue.
Asked about potential trade wars with neighbouring countries, Greer said “the action that the president is talking about is about fentanyl, where we don’t want another single fentanyl death”.
“We need to come to an agreement on that,” he said, adding that Mexico and Canada appear willing to do so.
Trump has cited illegal immigration and the flow of fentanyl across US borders as a reason for seeking 25 per cent tariffs on Canada and Mexico – though a lower rate on Canadian energy – over the past weekend.
Canada for its part has countered that below one per cent of undocumented migrants and fentanyl entering the United States comes through its border.
