Qantas will offer sleep-enhancing tea and new amenity kits, mattresses and duvets to premium passengers as part of improvements to its international business class as it pursues its alliance with Emirates.

The airline has already announced it will match Emirates and provide chauffeur-driven cars for premium passengers taking long flights.

It now says it will provide a T2 wellbeing tea blend "designed to encourage sleep" as well as a mattress and duvet designed to make its lie-flat seats more comfortable.

Other enhancements include new service that allows customers to select their preferred meals up to 72 hours before departure. The airline said this would give customers access to a wider range of supper choices or the option to skip the service and go to sleep.

The airline's new amenity kits -- the toiletry bags airlines give to customers at the front of the plane -- were designed by Kate Spade New York and Jack Spade and include "an environmentally friendly biodegradable toothbrush".

Qantas International chief executive Simon Hickey said the changes were being made because customers had told the airline they wanted greater choice and the ability to maximise their sleep.