BMW is adding 1,000 jobs at a plant in South Carolina, its largest production facility in the world.

The German car company announced Monday that it will invest $600 million at the plant in Spartanburg, which produced 411,000 vehicles last year and employs about 9,000 people. BMW will add the jobs by 2021.

About 70% of the vehicles made at the plant are sent to other countries, helping make BMW the largest vehicle exporter from the United States.

BMW chairman Harald Krüger credited "free trade and open markets" with making the plant a success.

"We will keep investing in our people and in our business in the U.S.," he said in a statement. "Therefore, I remain confident that our footprint and commitment will continue to grow not only in the great state of South Carolina, but also in the United States in the years to come."

BMW made the announcement as the plant celebrated its 25th anniversary. It makes cars for BMW's X3, X4, X5 and X6 lines, and it will make the BMW X7, which is coming to market late next year.

Related: Despite Trump's latest threat, BMW won't budge on Mexican plant

Even with its success in South Carolina, the company has been knocked by President Trump.

In January, he told a German news magazine that BMW should reconsider plans to build a $1 billion plant in Mexico. The automaker wants to build its BMW 3 Series sedan there starting in 2019. BMW has remained committed to that plant.