Air New Zealand has said problems with some of the Rolls-Royce engines on its aircraft have forced it to ground some international flights.

Rolls-Royce has advised the carrier that some of the Trent 1000 engines in the airline’s Boeing 787-9 fleet require maintenance sooner than previously indicated.

The engine manufacturer does not have any replacement engines available while this maintenance work is undertaken which means some schedule changes “unavoidable”, the carrier said.

Two flights were forced to return to Auckland this week after mechanical trouble, local media reported.

In addition to these changes, Air New Zealand is focused on securing replacement aircraft capacity.

Customers affected by these changes will be proactively contacted with new travel information.

In addition to this, the latest available information on any schedule changes will be published to the Travel Alerts section of the Air New Zealand website.

Customers are encouraged to check this first before calling the airline’s contact centre.