mexico city mexico president enrique pena nieto u.s. counterpart donald trump friday agree talk publicly payment wall american want build unite state southern border say mexico finance statement mexico government say phone call friday two hold constructive productive talk broach issue include u.s. trade deficit mexico flow illegal arm drug across border regard payment border wall presidents recognize clear public differences opinion sensitive subject agree resolve differences part comprehensive discussion aspects bilateral relationship statement say presidents also agree talk publicly controversial issue mexico u.s. agree talk publicly wall payment