The U.S. government has issued preliminary countervailing duties on structural steel from China and Mexico, sparing Canada. This case was filed before the relaxation of steel duties under the U.S.-Mexico-Canada Agreement and may therefore cause friction between the U.S. and Mexico. Exports from Mexico to the U.S. have rallied 16.8% year over year in the three months to May 31, whereas Chinese exports that have dropped 44.0%. The leading shipper to the U.S. in the 12 months to May 31 was Valmont with 34,300 tons from Mexico, mostly by land. In terms of seaborne shipments Tenaris was la...