Currently, vaccinated international travellers arriving into the US can present a negative result obtained within three days from their point of departure.
The new one-day testing requirement would apply to US citizens as well as foreign nationals.
The Biden administration is also considering whether to require air travellers to get another test within three to five days after arrival, officials said.
While the Centres for Disease Control (CDC) did not confirm that, it noted it continues to recommend all “travellers should get a Covid-19 viral test 3-5 days after arrival” and “post-travel quarantine for any unvaccinated travellers”.