FRANKFURT — Volkswagen may buy back some diesel cars in the United States if it cannot make them compliant with air quality rules fast enough, a lawyer for the company says.

The statement, made during a court hearing by Robert Giuffra, a lawyer defending Volkswagen against class-action suits by owners of tainted diesel vehicles, was the clearest indication yet that the company, which is based in Wolfsburg, Germany, may not have the technology to bring emissions for some of the cars into line with regulations without hurting performance and fuel economy.

Mr. Giuffra spoke during a hearing in United States District Court in San Francisco last week, although his remarks did not attract wide attention at the time. Volkswagen officials have indicated that the company might buy back some cars in the United States. Mr. Giuffra’s comments suggested that option has become more likely.

Volkswagen could probably find a solution eventually, Mr. Giuffra said. He added, “The question though is one of timing.