Japanese telecommunications giant SoftBank Group plans to invest $50 billion in the U.S. economy and add 50,000 jobs, President-elect Donald Trump announced Tuesday. Trump appeared in the lobby of the Trump Tower with Masayoshi Son, the chief executive of SoftBank, to announce the news, and later put it out on Twitter. Son did not say what specific investments SoftBank would make. While talking to reporters, he held up a piece of paper with the same figures that Trump had announced, but which also specified that the investment would be made over the next four years. In his unlikely march to the White House, Trump campaigned on bringing more jobs to America, particularly in manufacturing regions hit hard by the recession and globalization. The SoftBank deal is the second he has arranged to keep his promises to voters. Last week, he announced that the Carrier Manufacturing Corporation would keep 1,100 jobs in Indiana instead of outsourcing them to Mexico. WATCH: Trump Touts $50 Billion Investment in US by Japanese Investor In contrast, a shocking tweet from Trump on Tuesday could cost billions of dollars for one of the leading U.S. companies. The billionaire real estate mogul said he wants to cancel an order for a new Air Force One, the plane that flies U.S. presidents around the world. The government has contracted with the Boeing Company to construct at least two new planes, which would go into service in 2024. The planes initially cost about $3 billion, but the costs have reportedly been rising, prompting Trump to tweet "the costs are out of control." Boeing responded to Trump's criticism of the rising costs, saying in a statement that the contract is for $170 million, not the "more than $4 billion" included in Trump's tweet. "We are currently under contract for $170 million to help determine the capabilities of these complex military aircraft that serves the unique requirements of the president of the United States," the statement said. The statement from the aerospace giant suggested that the project is simply in one of several phases that must be completed during the development and building process. "We look forward to working with the U.S. Air Force on subsequent phases of the program, allowing us to deliver the best planes for the president at the best value for the American taxpayer." WATCH: Trump Slams Boeing for Pricey Air Force One Upgrade Following Trump's tweet, Boeing stocks slid by more than 1 percent in pre-market trade, according to CNBC. But Boeing's slide did not affect the president-elect's own bottom line because, according to his spokesman, Trump sold all of his stocks in June. "The president-elect sold all of his stock back in June. I do not know if he had any Boeing stock at that time," said Trump spokesman Jason Miller. A financial disclosure filed in May showed Trump owned Boeing stock valued at between $50,001 and $100,000. Trump's stock portfolio, which is separate from his broader real estate and branding businesses, accounted for a tiny fraction of his personal fortune. Most of his money is in real estate. Earlier this week outside Trump Tower, supporters of a three-state vote recount joined Green Party presidential candidate Jill Stein in a rally to ensure an "accurate, secure and fair" vote. "We are here to assure Donald Trump that there is nothing to be afraid of," Stein said. "If you believe in democracy, if you believe in the credibility of your victory, put down your arms, end your bureaucratic obstruction, end your intimidation and join we the people of America who are calling for a democracy that serves all of us and elections that we can trust." A judge has ordered a hand recount begin in Michigan, one of three battleground states that Stein believes may have been hacked due to aging voting machines. Similarly, she is pushing for a federal court order to enact a recount in Pennsylvania.