General Motors has ordered dealers to stop selling their current supply of certain models of the Chevrolet Cruze, but the automaker hasn't specified a reason.

As the company deals with a massive vehicle recall related to ignition switch issues, Chevrolet dealers received an email on Thursday that ordered a stop delivery on 2013 and 2014 Cruzes with 1.4-liter turbo engines, Jalopnik reported via The Wall Street Journal.

The Cruze is GM's top seller in the United States, and vehicles with the 1.4-liter turbo engine are the most popular version, CNNMoney reported.

The reason behind the halt hasn't been disclosed, and previously sold cars haven't been recalled, spokesman Alan Adler told CNNMoney.

GM has sold more than 2 million of the Cruze worldwide since its 2009 launch, including 248,000 models in the U.S. in 2013.

Because the carmaker had close to a 70-day inventory of Cruze models at the end of last month, CNNMoney estimates that around 7,000 vehicles around the country are part of the stop-delivery order.

Stop orders are fairly common in the industry and can be for extremely minor issues or major problems that later lead to recalls, Adler told CNNMoney.

The unusual aspect to the Cruze stop delivery is GM's issuing a halt without detailing a reason, according to Karl Brauer, senior analyst for sales tracker Kelley Blue Book.

The carmaker seems to be responding quickly to safety problems to insure against future debacles like the recent 1.6-million vehicle recall, which has led to a federal investigation.

"GM has to do more than appear to be making changes. They have to have verifiable shifts in how they handle safety issues," Brauer told CNNMoney. "What's the big problem with the ignition switch--that they didn't act quickly enough. Now they're responding at the first signs of any problem."

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