President-elect Donald Trump rode to TikTok’s rescue on Sunday, working on the eve of his new presidency to try to undo a ban effort that he helped initiate during his first term.The popular social-media app started restoring service on Sunday for its 170 million U.

Even if temporary, the unprecedented shutdown of TikTok is set to have a wide-ranging impact on U.S.-China relations, U.S. politics, the social media marketplace and millions of Americans.

During his first term as president, Donald Trump led the effort to ban TikTok, the hugely popular video-sharing site he said posed a threat to U.S. national security. But on the eve of his return to the White House,