The move would come at a time when Japan is expected to further ease its Covid-19 border controls, waiving visa requirements for certain tourists and removing a limit on daily arrivals.

Singapore, which is a major Asian financial and travel hub, lifted most pandemic curbs, including travel restrictions, earlier this year.

Pakistan has had very few Covid cases over recent months and had done away with almost all precautions.

Several major carriers, including American Airlines, Delta Air Lines and United Airlines, dropped mask mandates on domestic flights and some international flights following the ruling.

The president urges Americans who have not yet received their shot to do so, calling it a 'patriotic' act.

European countries to require medical-grade masks or respirators in public but other healthcare bodies disagree.

The study concludes that even on a full plane, the level of transmission over 12 hours of flight is negligible.