TikTok says it is in the process of restoring service to users in the United States after President-elect Donald Trump vowed to issue an executive order to try to pause the ban of its use.

TikTok is already available for some users. The message on TikTok says, "As a result of President Trump's efforts, TikTok is back in the US.!"

The video-sharing app has temporarily shut down as a law banning it took effect on Sunday. The law prohibits IT firms from providing downloads and updates of TikTok in the US unless its China-based parent company, ByteDance, sells its US business. The firm had announced it was temporarily suspending its service in the US before the law took effect.

In a post on his Truth Social site on Sunday, Trump said he will issue an executive order when he takes office on Monday "to extend the period of time before the law's prohibitions take effect."

The statement also said the order will also confirm that "there will be no liability for any company that helped keep TikTok from going dark before my order."

It continued to say: "I would like the United States to have a 50 percent ownership position in a joint venture. By doing so, we save TikTok, keep it in good hands."

TikTok said in a statement on Sunday Trump provided the "necessary clarity and assurance" to the company's service providers that "they will face no penalties providing TikTok" to users in the US."

It also said, "We will work with President Trump on a long-term solution that keeps TikTok in the United States."