"The investment is funded by Walmex and is necessary for expansion of Wal-Mart's Mexican business," she said.
Warner did not comment on whether Wal-Mart had heard from Trump after it made the announcement in Mexico. She said the investment is not the same as companies moving jobs to Mexico.
Recently, United Technologies Corp's Carrier unit decided to keep half of the 2,100 Indiana jobs it was to shift to Mexico after the U.S. president-elect worked out an agreement with the company's CEO, Gregory Hayes.
The election has thrown Mexico's business world into uncertainty, as Trump has attacked U.S. companies investing south of the border and threatened to renegotiate or scrap a major trade agreement with Mexico.
A large part of Wal-Mart's investment will be over the next three years, including in back-end infrastructure, said the company's chief executive, Guilherme Loureiro. He said it would create some 10,000 permanent new jobs.
"It will involve the building of new distribution centers, as well as the expansion of ones we already have," he said at an event with President Enrique Pena Nieto at the president's office.
Loureiro said the company had already invested 80 billion pesos ($3.93 billion) in the past four years.