The agency, nonetheless, said it would re-evaluate the cases and take action if warranted.

The Times found that the auto companies conducted at least 33 safety actions in foreign countries that never fully led to American recalls. The defects involved such critical parts as airbags, brakes and steering and electrical systems.

In one case, the safety agency opened an investigation into a power steering problem in Toyota models in November 2006, but closed it the following March, despite having found three crashes potentially tied to the problem and more than 100 related warranty claims.

In its closing report on the inquiry, the agency said it would “continue to monitor complaints and other information relating to the alleged defect.” A year and a half later, Toyota recalled the vehicles in China and cited the National Highway Traffic Safety Administration’s closed investigation as evidence that an American recall was unnecessary.

The Times identified at least nine additional foreign actions by the automakers that did result in full recalls in the United States, but well after the period during which they were required by law.

One foreign recall conducted by Honda was followed by an American recall more than five years later. G.M. issued two United States recalls in 2014 that followed Canadian recalls from 2012. In one of those, the company had recalled models of the Chevrolet Aveo and Pontiac G3 in 67 countries for a corrosion problem that could cause brakes to stop working properly, but recalled the American cars only last July.

“If cars are unsafe in Canada, they’re unsafe here,” said Rosemary Shahan, president of Consumers for Auto Reliability and Safety, an advocacy group, when told of The Times’s findings. “It’s not believable that suddenly you cross a border into Maine and suddenly your car is safe.”

In some cases, auto companies sent less urgent alerts, known as technical service bulletins, to American dealers — and on rare occasions, customers, too — instead of ordering recalls, even though those notices are not supposed to be used to correct serious safety problems.