Twitter Inc. has approached TikTok's Chinese owner ByteDance to express interest in acquiring the U.S. operations of the video-sharing app, two people familiar with the matter said, as experts raised doubts over Twitter's ability to put together financing for a potential deal.

It is far from certain that Twitter would be able to outbid Microsoft Corp. and complete such a transformative deal in the 45 days that U.S. President Donald Trump has given ByteDance to agree to a sale, the sources said on Saturday.

The news of Twitter and TikTok being in preliminary talks and Microsoft still being seen as the front-runner in bidding for the app's U.S. operations was reported earlier by The Wall Street Journal.