CANTON, Miss. — The United Automobile Workers — desperate to make inroads in the anti-union South where Toyota, Volkswagen and other foreign automakers have assembly plants — has never tried a unionization drive quite like the one at the Nissan plant here.

It has enlisted thousands of union members in Brazil to picket Nissan dealerships there as the company prepares to co-sponsor the 2016 Olympics in Rio de Janeiro. The union has sent a team of Mississippi ministers and workers to South Africa, where Nissan has an assembly plant, to try to embarrass the company with accusations that it violates workers’ rights at the Canton plant.

Over the next few weeks, a delegation of U.A.W. leaders and supporters will travel to Tokyo, and to Paris, where Renault, Nissan’s partner, is based, to publicize a report by a Cornell University professor that asserts that Nissan’s managers have illegally threatened to close the Mississippi plant if workers vote to unionize.

These efforts are largely directed at Nissan’s part-Brazilian, part-French chief executive, Carlos Ghosn, a renowned cost cutter who has said the company prefers communicating with its Mississippi workers without a union.