Dywedodd Mr Miles unwaith eto nad oes mandad ar gyfer Brexit heb gytundeb, ac y byddai rhwygo'r wlad o'r UE heb gytundeb yn niweidio economi Cymru yn fwy nag unman arall.
Mr Miles also reaffirmed his belief there remains no mandate for a no deal Brexit, and that crashing out without a deal will disproportionately damage the Welsh economy.