Congress and President Joe Biden agreed months ago to outlaw TikTok from operating in the US under Chinese ownership. Donald Trump’s reelection could throw a potential wrench into that plan.

Trump’s statements on the campaign trail suggest he may at least try to tinker with the impact of a law signed by Biden in April that makes Chinese ownership of the app illegal.

The law, called the Protecting Americans from Foreign Adversary Controlled Applications Act (PAFACAA), gives TikTok’s Chinese owner, ByteDance, an ultimatum to either sell TikTok to a US owner or have it banned from operations in the country.

Biden set Jan. 19, a day before Trump is scheduled to be sworn into office, as a deadline for the required divestment — unless the company is able to overturn the law in a court case currently playing out in Washington, D.C.

Once back in office, President-elect Trump could ask Congress to undo the law. His chances to do so, if he chooses, may have improved this past week after it was confirmed that Republicans secured enough votes to control both chambers of Congress.

In September, the president-elect suggested in a post to his social media website, Truth Social, that he would "save TikTok" and prevent federal law enforcement from shuttering the app.

"We’re not doing anything with TikTok, but the other side is going to close it up, so if you like TikTok, go out and vote for Trump," the former president said in the post.

One political complication for Trump is that he spent his time in office and on the campaign trail promising to protect Americans and US industry against Chinese espionage and other economic threats.

But Trump-Vance transition team spokesperson Karoline Leavitt, when asked about TikTok, indicated that the president-elect would follow through on what he pledged.

She told Yahoo Finance that “the American people reelected President Trump by a resounding margin giving him a mandate to implement the promises he made on the campaign trail. He will deliver.”

ByteDance isn’t necessarily waiting on a new Trump administration to save TikTok. It has asked the District of Columbia’s US Court of Appeals to evaluate the constitutionality of the law.

The appeals court heard arguments from both sides on Sept. 16, and lawyers for the Justice Department asked the judges to issue their ruling by Dec. 6.

The court could issue a decision either before or after Trump’s inauguration. The losing side could also appeal the result to the Supreme Court, which has a conservative majority.

ByteDance’s argument to the appeals court is that the law ran afoul of the First Amendment’s free speech protections, the Fifth Amendment’s takings clause, and protections against bills of attainder — also known as ex post facto laws that deem previously legal activity as illegal and then reach back in time to punish violators for past actions.