GM Jobs Touted by Trump Were in Works for Years

President-elect Donald Trump took to Twitter this morning to once again take credit for General Motors' decision to add or keep thousands of American jobs, saying the jobs "came back because of me!"

Trump went a step further by calling an NBC News report on the automotive giant's decision "fake news" because he said it failed to mention his role in the move.

GM's plans to add or keep 7,000 American jobs and invest $1 billion in United States manufacturing, which were announced Tuesday and later touted by Trump on Twitter, were actually "years in the making," according to the company.

In a statement, GM said the investments will "cover multiple new vehicle, advanced technology and component projects," culminating in 1,500 jobs. The Detroit-based manufacturer said it also intends to shift some production work from Mexico back to the U.S.

The timing of the announcement raised suggestions that claims by Trump contributed to the company's actions. Throughout his presidential campaign and ensuing transition, Trump made the collapse of American manufacturing and outsourcing of jobs -- particularly to Mexico and China -- a focal point of his platform and his administration's plans.

Just two weeks ago, Trump criticized GM -- whose brands include Chevrolet, Buick, GMC and Cadillac -- on Twitter, writing that the company was "sending Mexican made model of Chevy Cruze to U.S. car dealers-tax free across border," and threatened a tariff if it did not choose to make the cars in the U.S.

But a GM spokesperson said Tuesday that "product development decisions are made well in advance" and that "today's announcement is no different."

When questioned what role Trump played in the development, the spokesperson added that "all of the decisions behind today's announcement are good business decisions and they have been in the works for some time."

Nevertheless, the president-elect appeared to take credit for the action.

"With all of the jobs I am bringing back into the U.S. (even before taking office), with all of the new auto plants coming back into our..... country and with the massive cost reductions I have negotiated on military purchases and more, I believe the people are seeing 'big stuff,'" he wrote.

On Tuesday afternoon, Trump specifically called attention to GM's announcement in an additional tweet, writing, "Thank you to General Motors... for starting the big jobs push back into the U.S.!"

In reference to a Trump tweet from Jan. 3, GM said Tuesday that "today's announcement has no bearing on the Cruze." The company previously insinuated that the president-elect's tweet was factually incorrect, saying it assembles the Cruze sedan in the United States for the domestic market and the hatchback version in Mexico for foreign markets.

Despite Trump's previous criticism, domestic job creation and investment are not entirely new developments for the company. In the release, GM notes that it had previously announced a $2.9 billion investment in 2016 and has put $21 billion into its domestic operations since 2009.

Moreover, in the last four years, the company has "created 25,000 jobs in the U.S." and "added nearly $3 billion in annual wages and benefits to the U.S. economy," according to their statement.

"As the U.S. manufacturing base increases its competitiveness, we are able to further increase our investment, resulting in more jobs for America and better results for our owners," said GM Chairman and CEO Mary Barra in a press release. "The U.S. is our home market and we are committed to growth that is good for our employees, dealers, and suppliers and supports our continued effort to drive shareholder value."

Last month GM said it would reduce its workforce by 1,300 at a plant in Detroit come March 2017, and would temporarily cut production at additional U.S. factories in January.

ABC News' Katherine Faulders contributed to this report.