 That year, the ABC nations intervened in a diplomatic dispute between the United States and Mexico who were on verge of war over the Tampico Affair and the subsequent occupation of Veracruz by US forces.The ABC nations meet with representatives of the United States and Mexico in Niagara Falls, Canada to ease the tension between the two nations and to avoid war, which afterwards did not occur.In 1960, President Adolfo López Mateos became the first Mexican head-of-state to pay a visit to Chile.