TikTok's bid to overturn a law which would see it banned or sold in the US from early 2025 has been rejected.

The social media company had hoped a federal appeals court would uphold its argument that the law was unconstitutional.

TikTok's lawyers told the court in September that a ban would have a "staggering" impact on the free speech of its users.

But the court ruled the law "was the culmination of extensive, bipartisan action by the Congress and by successive presidents."

The law was "carefully crafted to deal only with control by a foreign adversary, and it was part of a broader effort to counter a well-substantiated national security threat posed by the PRC (People's Republic of China)," the ruling continues.

The US wants TikTok sold or banned because of what it says are its owner's links to the Chinese state - links TikTok and parent company Bytedance have always denied.

But the US has previously stated its concerns that user data is vulnerable to exploitation by China's government.

TikTok and ByteDance have previously stressed that they will not sell the platform.

They are yet to react to this ruling.

The US Court of Appeals' District of Columbia Circuit striking down its petition to review the law means that the platform is set to be made unavailable to US users from 19 January.

However, President-elect Donald Trump, who unsuccessfully tried to ban TikTok during his first term in 2020, said before the November elections he would not allow the ban on TikTok, meaning even after this ruling its future remains unclear.