President Donald Trump on Monday blocked Broadcom Ltd.’s $117 billion hostile bid for Qualcomm Inc., capping a remarkable series of moves by the Trump administration reflecting officials’ concerns about an intensifying arms race between the U.S. and China over advanced technologies.

While Broadcom is a Singapore-based company, the U.S. panel that vets foreign deals said that the bid could have had implications for the U.S.’s broader technological competition with China. That panel, the Committee on Foreign Investment in the...