Twitter has approached TikTok's Chinese owner ByteDance to express interest in acquiring the US operations of the video-sharing app, according to reports.

It comes as experts raised doubts over Twitter’s ability to put together financing for a potential deal in the 45 days that US President Donald Trump has given ByteDance to agree to a sale.

Microsoft is still being seen as the front-runner in bidding for the app's US operations.

Twitter has a market capitalisation of close to $30 billion, almost as much as the valuation of TikTok's assets to be divested, and would need to raise additional capital to fund the deal, according to the sources.

"Twitter will have a hard time putting together enough financing to acquire even the US operations of TikTok. It doesn’t have enough borrowing capacity", said Erik Gordon, a professor at the University of Michigan.

"If it (Twitter) tries to put together an investor group, the terms will be tough. Twitter's own shareholders might prefer that management focus on its existing business", he added.

TikTok has come under fire in the US over national security concerns surrounding data collection.

Last week, Mr Trump unveiled bans on US transactions with the China-based owners of messaging app WeChat and TikTok, escalating tensions between the two countries.

Mr Trump said he would support Microsoft's efforts to buy TikTok’s US operations if the US government got a "substantial portion" of the proceeds. He nevertheless said he will ban the popular app on 15 September.

Microsoft said yesteday it was aiming to conclude negotiations for a deal by mid-September.