After months of international controversy over possibly defective Takata Corp. air bags, one thing lawmakers, regulators, the media, carmakers and the parts supplier probably agree on is this: It won’t be easy to resolve the crisis.

While Takata Chief Executive Officer Shigehisa Takada has avoided public appearances since June, a person close to the company’s thinking said it will continue to “thoroughly” conduct tests to determine the cause of the trouble with its inflators, which in some cases can deploy with too much force and spray shrapnel at those onboard.

The Takata management has been briefed almost every day on the results of testing on its recalled air bags but has so far not been informed of any problem, the person said.

“We understand the public’s concerns and we take them seriously,” Takata said in a newspaper ad published in the United States and Germany this month under the name of its CEO.

But the firm also indicated that it will not jump to any conclusions without scientific evidence. The ad continued, “We are dramatically increasing the testing and analysis of inflators retrieved from the safety campaigns to inform our understanding of the problem and to help chart the best strategy for addressing it.”

At least five deaths — four in the United States and one in Malaysia — have been linked to problems with Takata air bags, while more than 20 million cars are subject to mass recalls issued by Honda Motor Co., Takata’s biggest customer, and Toyota Motor Corp., since 2008.

The possibly time-consuming approach and the “disappearance” of the company’s chief executive have increased criticism of the Tokyo-based firm, and some accuse it of not being serious enough.

Analysts say Takata has a long history of failing to properly communicate with the market, including the carmakers it supplies as well as drivers, since the problem emerged in the early 2000s.

“It is always important to establish steps to address a problem in the bud, but they always fail to do that,” said Takaki Nakanishi, auto analyst at Nakanishi Research Institute.

While Takata bides its time and limits its recall campaign to hot and humid regions of the United States, defying pressure from U.S. lawmakers, Honda and other carmakers are expanding their recalls.

Experts say the Takata problem arose from a failure by carmakers and parts suppliers to understand the characteristics of the chemicals used to inflate the bags and their links to certain conditions, such as temperature and humidity. This could mean carmakers feel forced keep calling back products without knowing exactly what happened.

In contrast, Takata hopes to take a scientific approach first, checking on the parts’ manufacturing process and examining its quirky preference for ammonium nitrate — a bomb-making chemical used as propellant — and the chance it could degrade when exposed to moisture.

The automakers have begun searching for ways to improve the situation.

“It is regrettable that carmakers did not have knowledge on explosives,” Japan Automobile Manufacturers Association Chairman Fumihiko Ike, who is also chairman of Honda, told a recent press conference, referring to ammonium nitrate, which is commonly found in fertilizer and explosives.

Ike said Japanese carmakers are discussing whether to let drivers regularly replace the chemicals used in air bags, as they have also done for warning flares in vehicles.