New Zealand MPs had visited the democratically governed island for decades without a problem, a spokesperson for Foreign Minister Winston Peters said.
"Such visits are not inconsistent with New Zealand's One China policy," the spokesperson said on Thursday, referring to its policy since 1972 of recognising Beijing as the sole government of China.
"In the context of that long history, the minister was surprised to learn that China has taken a decision to, for the first time, impose travel bans on New Zealand MPs as a result of travel to Taiwan."
Peters instructed New Zealand foreign ministry officials in Beijing and Wellington to discuss the matter with Chinese authorities "in order to express concern at this departure from past practice and to better understand it".
Taiwan's foreign ministry said it strongly condemned China's "retaliatory" measures for the MPs' visit in May, adding that Beijing had no right to interfere in Taipei's interactions with "international friends."
New Zealand and China have maintained a largely stable relationship in recent years, with China remaining New Zealand's largest trading partner, even as Wellington has grown more outspoken about Beijing's expanding influence in the Pacific.
Senior politicians from both countries have exchanged a number of visits during the past three years, with New Zealand Prime Minister Christopher Luxon visiting China in 2025.
China views Taiwan as its own territory, and has not ruled out the use of force to take control of the island. Taiwan's government rejects Beijing's sovereignty claims.
"MPs are not ordinary citizens," said a spokesperson from the Chinese embassy in New Zealand in a statement on its website.
"China has consistently opposed visits to China's Taiwan region by members of the legislatures of countries that have established diplomatic relations with China, including New Zealand, and this case is no exception."
The Chinese embassy informed MPs that four MPs had been banned from entering China, Hong Kong and Macau for a year, according to an email from the Office of the Clerk, which administers New Zealand's parliament.
The ban targeted three MPs from the ruling conservative coalition, Laura McClure, David Wilson and Maureen Pugh, along with opposition Labour MP Duncan Webb.
McClure told The New Zealand Herald the travel ban was "a type of foreign interference".
"I'm not going to apologise for visiting Taiwan," she said.
The Chinese embassy told New Zealand parliament officials the travel ban could be reduced or waived if the MPs apologised for the trip, the email said.
A New Zealand parliament official confirmed a meeting with Chinese embassy representatives but did not disclose details.
Like most countries, New Zealand has no formal ties with Taiwan.
