By Ben Casselman and Adam Satariano • New York Times News Service

Amazon said Thursday it planned to spend $700 million to retrain about a third of its American workers to do more high-tech tasks, an acknowledgment that advances in technology are remaking jobs in nearly every industry — and that workers will need to adapt or risk being left behind.

Amazon said the program amounted to one of the world’s largest employee-retraining efforts. It will apply across the company, retraining about 100,000 by 2025. Amazon has about 300,000 employees in the United States.

With unemployment low and workers scarce, companies like Amazon feel pressure to look internally to fill their labor needs. Their efforts could help answer a more fundamental question: Will automation be a solution for the great challenges of the 21st-century economy — low wages, rising inequality and anemic overall growth — or make those problems worse?

“The scale and pace of the changes in the workforce are unprecedented,” said Susan Lund, an economist at the McKinsey Global Institute, the research arm of consulting firm McKinsey & Co. “They can’t hire off the street everyone they need. They have no choice but to retrain their own workers.”

The McKinsey Global Institute predicts that up to one-third of the American workforce will have to switch to new occupations by 2030.

So far, there is little evidence of widespread displacement. Amazon and other companies have hired hundreds of thousands of workers for their warehouses. Manufacturers have added jobs after decades of cuts.

Amazon’s announcement Thursday could be a sign that the strong labor market is finally pushing companies to make investments in both workers and technology to increase productivity.

Ardine Williams, Amazon’s vice president of people operations, said the company had more than 20,000 open positions in the United States.

Amazon isn’t trying to turn warehouse pickers into software engineers. Rather, its new program aims to move a large swath of workers up one or two rungs on the skills ladder, turning warehouse floor workers into IT technicians and low-level coders into data scientists.

Williams said the retraining initiative was built on existing education programs at the company. Software engineering classes will be available for corporate employees without technical backgrounds, she said.

Amazon’s announcement met with some skepticism from experts. They noted that U.S. companies had long spent less on training than their European counterparts — and that when they did offer training, it was usually for college-educated, white-collar workers.