General Motors (GM) and its joint ventures delivered 3,093,604 vehicles in China in 2019, down 15.1 percent from the previous year amid an overall sales downturn in the world's largest auto market.

GM said in a statement on Tuesday that the sharp decline was a result of "challenging environment with weakened consumer demand."

Only its Cadillac brand saw an increase of 3.9 percent in China. The deliveries of all other GM brands, including Buick and Chevrolet, posted year-on-year decline.

According to China Association of Automobile Manufacturers, the overall auto sales in China between January and November 2019 reached 23.11 million units, down 9.1 percent from the same period in the previous year.

"During the downturn, we are focused on bolstering our product lineup and improving cost efficiency to position our company for strong performance in China over the long term," said Matt Tsien, GM executive vice president and president of GM China.

"We expect the market downturn to continue in 2020, and anticipate ongoing headwinds in our China business," he added.

China has been GM's largest retail sales market since 2012. The leading U.S. automaker has in recent years sped up product launches and the upgrade of its brands to meet diverse demand in China.

GM said that it will keep up its launch cadence across brands in China this year, following the introduction of more than 20 new and refreshed models in 2019.

The launches will focus on luxury vehicles as well as midsize/large SUVs and MPVs, which have become the segments with the strongest increases in customer demand.