New Zealand Prime Minister Jacinda Ardern has told Kiwis in Victoria to activate their back-up plans after the state government announced a week-long lockdown.

Thousands of NZ residents are currently in Victoria, making use of the trans-Tasman bubble.

However, their route home was blocked when the NZ government paused its quarantine-free travel arrangement earlier this week after the COVID cluster began to emerge in Melbourne’s north.

On Tuesday, Ms Ardern’s government announced a 72-hour suspension on arrivals from Victoria.

On the basis of the growing cases – and the Victoria-wide snap lockdown announced on Thursday morning – Kiwi officials are widely expected to extend the pause when they review the suspension later on Thursday.

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In announcing the trans-Tasman bubble, Ms Ardern was clear that the border would open on a “flyer beware” approach, meaning travellers would need to make contingencies if such a lockdown emerged.

Speaking from Nelson on Thursday, Ms Ardern confirmed that approach.

“To any Kiwis who are in Melbourne, I know that they would have planned ahead had contingency just in case a scenario like this occurs,” she said, as reported by Stuff.

“Follow the guidance from local health authorities.”

NZ health authorities have contacted about 10,000 people who have recently arrived in the country from Victoria, advising them to be alert for COVID-19 symptoms.

Two people have volunteered they were in a location of interest; both have tested negative test.

The NZ government will give formal advice to Kiwis affected by the lockdown later on Thursday.

-AAP