washington u.s. president barack obama canadian prime minister justin trudeau mexican president enrique pena nieto meet ottawa north american leaders summit june 29 white house say wednesday three amigos summit two key u.s. trade partner come obama grapple wave anti-free-trade sentiment stall ratification trans-pacific partnership tpp sweep 12-nation pact include canada mexico obama hop u.s. congress ratify deal leave office jan. 20. trade become lightning rod issue presidential election campaign replace republican donald trump party presumptive nominee 2016 attack tpp describe tripartite north american free trade agreement disaster need renegotiate break democratic campaign senator bernie sanders oppose trade deal democratic front-runner hillary clinton also express concern canada send 75 percent export unite state would suffer greatly future president move clamp free trade trudeau ask would deal president trump say leaders countries would always agree need growth prosperity one important way achieve trade add level integration canadian american economies unlike anything else ... world tell news conference ottawa last three amigos summit toluca mexico 2014. canada suppose host meet early last year cancel amid tension prime minister stephen harper obama keystone xl pipeline obama address canada parliament visit white house say last come canada bilateral visit february 2009 first foreign trip presidency ottawa relations mexico strain canadian rule introduce harper impose visa visit mexicans trudeau say hop able announce within weeks requirement would scrap 'three amigos obama trudeau pena nieto meet june 29