negotiators canada mexico unite state meet second round talk renegotiate north american free trade agreement amid threats u.s. president donald trump pull deal nafta first implement 1994 eliminate tariff trade unite state canada mexico critics say draw job u.s. canada mexico workers badly pay supporters say create u.s. job loss manufacture unite state china mexico key issue face negotiators include nafta say order good trade duty-free within three countries must contain certain percentage north american content differ various products rule origin contentious auto industry cars must contain least 62.5 percent american canadian mexican content unite state want increase content threshold nafta goods bid return manufacture job unite state auto industry concede rule update account auto components exist original deal sign canada say prepare discuss strengthen rule origin auto sector change must apply equally three countries mexico will look strengthen rule warn go far make region less competitive unite state seek ditch so-called chapter 19 tool binational panel hear complaints illegal subsidies dump issue bind decisions unite state frequently lose case since nafta come effect 1994 mechanism hind purse anti-dumping anti-subsidy case canadian mexican company washington also argue chapter 19 infringe sovereignty domestic laws canada say chapter 19 update say dispute settlement mechanism red line must part update nafta mexico also say dispute settlement mechanisms vital part deal give investors security u.s. negotiators seek allow u.s. seasonal produce growers file anti-dumping case mexico seasonal fruit vegetable growers southeastern unite state come increase pressure year-round mexican import nafta seek ability pursue anti-subsidy anti-dumping case seek temporary import quotas u.s. retailers food industry group argue american producers could leave open retaliatory measure complaints file instance avocados tomatoes produce import mexico quotas feature nafta several agricultural commodities include dairy sugar washington seek eliminate non-tariff barriers u.s. agricultural export notably u.s. president donald trump call canada restrictions dairy import disgrace although dairy exclude original 1994 deal unite state seek eliminate non-tariff barriers agricultural export unite state seek provision deter currency manipulation washington want mechanism ensure nafta countries avoid tinker exchange rat gain competitive advantage neither canada mexico u.s. treasury currency manipulation watch list critics say u.s. demand attempt get currency manipulation global trade agreement establish precedent trade partner include china unite state push governments canada mexico open tender process u.s.-made products time defend exist buy american procurement laws buy american provision block use canadian steel build u.s. bridge canada push free market government procurement mexico say expect government procurement already include nafta part renegotiation investor-state dispute settlement unite state propose minor tweak nafta chapter 11 provision design ensure firm invest abroad receive fair equitable treatment foreign governments chapter 19 opponents provision argue infringe sovereignty benefit multinational corporations canada want update mechanism allow governments regulate interest environment labor comprehensive economic trade agreement canada recently negotiate european union factbox key issue nafta renegotiations