TikTok said on Sunday it was restoring its service after US President-elect Donald Trump said he would revive the app's access in the United States when he returns to power on Monday.

"As a result of president Trump's efforts, TikTok is back in the US," the platform said in a message to users.

TikTok also issued an earlier statement after US users reported being able to access the Chinese-owned service's website, while the far more widely used TikTok app itself began coming back online for some users with just a few basic services.

"In agreement with our service providers, TikTok is in the process of restoring service," TikTok said in the earlier statement that also thanked Trump for "providing the necessary clarity and assurance to our service providers that they will face no penalties (for) providing TikTok to over 170 million Americans and allowing over 7 million small businesses to thrive."

TikTok stopped working for US users late on Saturday before a law shutting it down on national security grounds took effect on Sunday.

Trump said he would "extend the period of time before the law's prohibitions take effect, so that we can make a deal to protect our national security."

"I would like the United States to have a 50 percent ownership position in a joint venture," he wrote on Truth Social.

Trump said the executive order would specify there would be no liability for any company that helped keep TikTok from going dark before his order.

Trump had earlier said he would most likely give TikTok a 90-day reprieve from the ban after he takes office, a promise TikTok cited in a notice posted to users on the app. (Reuters)