WELLINGTON (Reuters) - An Air New Zealand flight bound for Shanghai was turned back because of an “administrative issue” and the incident holds no political implications for ties with China, New Zealand Prime Minister Jacinda Ardern said on Monday.

FILE PHOTO - New Zealand's Prime Minister Jacinda Ardern reacts during a joint news conference with European Commission President Jean-Claude Juncker in Brussels, Belgium January 25, 2019. REUTERS/Yves Herman

The flight, with about 270 passengers, left Auckland just before midnight on Saturday but turned around several hours into its journey and landed in New Zealand on Sunday, the national carrier, part-owned by the government, has said.

“I think it is important to be really clear and not confuse administrative and regulatory issues as issues to do with the relationship,” Ardern told a weekly news conference.

“This was very much an administrative issue,” she added. “There’s an expectation that inbound aircraft be registered, that the flight in question had not fulfilled the administrative requirements.”

In a statement late on Sunday, China’s civil aviation regulator quoted the airline as having said the issue was due to “temporary improper allocation of the aircraft”.

In Beijing on Monday, foreign ministry spokeswoman Hua Chunying told reporters her understanding was that the plane had never registered in China.

Ardern’s remarks followed questions by some politicians and analysts whether the incident pointed to broader issues in New Zealand’s ties to its key trading partner.

“We need to know what has happened here. Is it part of the ongoing deterioration in relations between this New Zealand government and China?” opposition National Party leader Simon Bridges wrote on social network Twitter on Sunday.

In November, New Zealand’s intelligence agency rejected the telecommunication industry’s first request to use Chinese telecoms giant Huawei’s equipment in its planned 5G mobile network, citing national security concerns.

That followed a defense policy statement in July, in which New Zealand said China’s rising influence in the South Pacific could undermine regional stability, and alluded to tension in the disputed South China Sea, sparking complaint from China.

“There’s a heightened degree of sensitivity around the relationship right now,” said David Capie, director of the Centre for Strategic Studies at Victoria University of Wellington.

“On a range of issues with China this government has signaled it’s taking a different stance to its predecessor, so I think people are waiting to see if and how Beijing responds.”

The rescheduled flight landed in Shanghai on Monday, data from flight tracking website FlightAware shows.