President Donald Trump will not let Broadcom proceed with a blockbuster hostile takeover of Qualcomm.

Trump issued an executive order on Monday that prohibits Broadcom from acquiring Qualcomm for roughly $117 billion, citing national security concerns.

“The proposed takeover of Qualcomm qcom by the Purchaser is prohibited, and any substantially equivalent merger, acquisition, or takeover, whether effected directly or indirectly, is also prohibited,” the executive order, signed by Trump, said.

The order also said that Broadcom’s avgo 15 proposed candidates to Qualcomm’s board of directors have been “disqualified,” Qualcomm has previously rejected Broadcom’s proposed director nominees to its board.

Trump cited in the order that there is “credible evidence” that causes him to believe that Broadcom—if able to purchase Qualcomm—“might take action that threatens to impair the national security of the United States,” although he didn’t elaborate on the evidence. Broadcom is in the process of reincorporating in San Jose, Calif. It is currently based in Singapore.

Last week, the U.S. Committee on Foreign Investment said it was considering investigating the proposed Broadcom deal citing national security concerns, which ended up delaying a March Qualcomm shareholder meeting. As a response, Broadcom publicly accused Qualcomm of “secretly” asking the committee to investigate the deal, which Qualcomm then denied.

The White House statement directs Broadcom and Qualcomm to “immediately and permanently abandon the proposed takeover,” and verify in writing to the foreign investment committee that they have indeed terminated the deal and any such variation.

A possible combination of Broadcom and Qualcomm would have created a massive wireless and mobile semiconductor giant with a market cap of over $200 billion. Such a huge semiconductor company was enough to worry Intel intc , which the Wall Street Journal reported last week was considering buying Broadcom if the deal actually went through.

Get Data Sheet, Fortune’s technology newsletter.

President Trump’s executive order puts an end to Broadcom’s unsolicited pursuit of Qualcomm. Qualcomm had repeatedly rejected Broadcom’s bids, citing national security concerns and a belief that the deal undervalues the company.

Daniel Ives of GBH Insights said in a research note that while Broadcom could potentially challenge the order, it’s not likely to make a difference. He wrote that “the Trump edict essentially kills any chances of this deal happening and is a major gut punch to those Qualcomm bulls hoping this soap opera could end with a bid following pressure from the shareholder meeting, which is poised to happen next month after getting delayed.”