Dertroit, Michigan - Ford is investing $700 million to expand its Flat Rock assembly plant and hire 700 new hourly workers to build self-driving and electric vehicles along with the Mustang and Lincoln Continental already produced at the Downriver site.

The automaker also said on Tuesday that it is canceling plans for a new $1.6 billion plant in San Luis Potosi, Mexico, but confirmed that the next-generation of its Focus compact will be produced at its Hermosillo, Mexico factory.

Ford CEO Mark Fields said the decision to cancel the plant in Mexico was in part related to the need to "fully utilize capacity at existing facilities" amid declining sales of small and medium sized cars, as well as the pro-business climate the automaker expects under President-elect Donald Trump and the Republican led Congress.

Ford was repeatedly under fire from Trump during last year's presidential campaign for its decision to move production of small cars to Mexico even though virtually all other auto makers are also expanding and building new plants there.

Also on Tuesday, Trump threatened to impose a "big border tax" on General Motors Co for making some of its Chevrolet Cruze cars in Mexico.