Prime Minister Jacinda Ardern said New Zealand will suspend its quarantine-free travel arrangement with Australia for at least eight weeks starting Friday night, as Australia battles an outbreak of the highly contagious Delta virus variant.

“We’ve always said that our response to the pandemic would evolve as the virus evolved. This is not a decision we have taken lightly, but it is the right decision to keep New Zealanders safe,” Ardern told reporters in Auckland.

The “travel bubble” had already been paused for travellers to and from New South Wales, Victoria and South Australia.

Asian countries have kept their borders mostly closed during the pandemic, and the bubble was a rare quarantine-free arrangement. Plans for a Singapore-Hong Kong bubble have been delayed several times.

Demand for flights between Australia and New Zealand has been more subdued than anticipated since the bubble opened on April 19.

Scheduled airline capacity between Australia and New Zealand this month is about 44% of 2019 levels, according to data from aviation analytics firm Cirium, well below initial forecasts of more than 70%.