Prime Minister Jacinda Ardern will head to the United States on Monday night - but her recent bout of Covid-19 has put at risk her first White House visit and meeting with US President Joe Biden. 

Ardern was expected to visit the White House on her trip but strict White House protocols around Covid-19 have thrown things into doubt. 

Ardern said the issue was her recent infection with Covid-19 rather than any unwillingness to meet on either side. No other country's leader had had Covid-19 so soon before going to the White House and that had resulted in uncertainty. 

Officials have been trying to secure a slightly later date for a meeting - that is yet to be confirmed, but there is optimism it will now take place next week after the rest of her visit in the US. 

If so, Ardern will extend her time away for it by another two days. 

It would be the first White House visit for a Prime Minister since John Key went to see then President Barack Obama in 2014. 

Covid-19 has meant Ardern and Biden have not met in person since Biden was elected President in early 2021, although they have had phone calls and virtual meetings. 

Ardern's positive Covid result also meant she had to delay her departure by a couple of days to meet the US requirement of a 10-day wait after testing positive. That meant events, including to promote the film industry in Los Angeles, had to be scrapped and Ardern will instead start in New York. 

Ardern said the logistical headaches her Covid had resulted in were just a part of dealing with the virus these days. 

"So there are a few challenges that come with that and in these times you roll with the Covid curveball that you are thrown. 

"That doesn't mean we don't crack on with the job." 

Ardern will meet with members of the US Senate in DC as part of her trip, which includes New York, Boston, Seattle, Washington DC and San Francisco. Highlights of her itinerary include the Harvard University Commencement Ceremony address, a repeat appearance on Stephen Colbert's The Late Show, and meetings with tech and social media giants including Twitter, Microsoft and Google. 

Ardern said she could not imagine a more important time for political engagement with the US as Biden moved to do more in the Indo-Pacific - a region in which China is also active. 

Prime Minister Jacinda Ardern attends Question Time in Parliament via Zoom as she isolates after contracting Covid-19. Photo / Parliament TV 

Biden is expected to firm up his proposal for an Indo Pacific Economic Plan - something Ardern has said New Zealand was likely to sign up for. 

However, in her pre-trip interview, she made it clear that it fell short of what New Zealand wanted from the US on trade - and that the CPTPP was still the primary goal. 

"That does not mean we will back off the CPTPP because that is where we see an existing framework that is a high-quality agreement and that sets a high standard we know is beneficial to our exporters." 

She acknowledged Biden's interest in the Indo-Pacific compared to former US President Donald Trump. 

"In the Pacific, really what we have called for is the return. The United States has been a present force in our region for a number of years. What we've seen in recent years, though, was a particular focus perhaps to other domestic matters or into other regions and slightly less of a presence in ours. 

"We've asked for that return, but not just that return - but for a wider interest particularly in the economic architecture that is growing and developing in our region and in which the US has been less present." 

New Zealand has long sought a free-trade agreement with the US, whether bilateral or through a wider agreement such as the CPTPP. Former President Obama had championed it but Trump pulled the US out of it in 2017. 

While in the US, Ardern said she would also take every opportunity she could in an "unashamed" pitch to get tourists to come back to New Zealand. That would include a repeat appearance on Stephen Colbert's The Late Show, and meetings with travel publications. 

Ardern said that in 2019 the US had been the third biggest market for incoming tourists to New Zealand. 

"So coming and sharing the message to come and spend their winter in our summer is a really compelling message to share right now." 

Pre-departure testing was set to be scrapped "relatively shortly" and before the full reopening in July. However, there was a Covid caveat - she said the border surveillance and screening programme could be brought back "rapidly" if required - such as if a new variant emerged. 

She noted New Zealand was not the only country with Covid-related travel requirements - and pointed to her own plight. "In fact, some might say the US is even more restrictive than New Zealand, with its 10-day rule. So it's not unusual. If anything ours sit in the middle of the pack." 

A trade and business delegation is travelling with her and the RNZAF Boeing will fly the delegation around the US.