China gaffe: Where in the world is Jacinda Ardern?

Prime Minister Jacinda Ardern apologised after muddling Japan and China at a press conference in Tokyo.

Prime Minister Jacinda Ardern has made an awkward faux pas after touching down in Tokyo - muddling Japan with China in her first media standup in the country.

Ardern said it was an "incredibly exciting time for New Zealand in its relationship with China - excuse me sorry, with Japan".

She reportedly blamed jetlag for her mistake, saying "You'll understand I've been on continuous travel and just this moment stopped here."

While the gaffe was understandable at the end of a long-haul flight it came at an awkward time.

Just yesterday the Asia New Zealand Foundation released a report questioning whether New Zealand had let its relationship with Japan "drift" amid trade differences and a shift in attention toward China's booming market.

But challenges in the international economic and security environment could provide a good reason for Japan and New Zealand to deepen their relationship, report author David Capie said.

"Uncertainty across the Asia-Pacific region has given both countries an interest in strengthening ties with partners that share common interests in the rules-based order."

The Prime Minister is in Japan to discuss trade and tourism with the country's Prime Minister Shinzo Abe as well as watching an All Blacks game at the Rugby World Cup

It's the first leg of a trip that will take her to the leaders' week at the UN in New York.

Ardern's visit is the first trip to Japan by a New Zealand Prime Minister since the CPTPP trading agreement was signed.

Japan hosting the Rugby World Cup was an opportunity for New Zealand to leverage its relationship with the Asian nation, which was our fourth largest two-way trading partner, Ardern said.

Japan was already New Zealand's sixth biggest tourism market but the RWC was a great opportunity for Tourism NZ to entice even more people to visit.