New Zealand universities have called on the government to exempt thousands of Chinese students from the travel ban sparked by the coronavirus crisis, saying it could them more than NZ$150m in tuition fees.

Chinese foreign students make up roughly half of all foreign students studying at New Zealand’s universities but are unable to get into the country for the start of the academic year. Orientation week begins next week.

On 2 February the government placed temporary restrictions on entry into New Zealand for all foreign nationals travelling from, or transiting through, mainland China.

The restrictions coincided with the usual peak travel period of lunar new year, and were extended at the weekend for another eight days by the health minister, David Clarke.

On Monday, China’s health commission revealed the total number of cases in the country now stood at 70,548, a rise of 2,048. Total deaths now stand at 1,770, after 105 more deaths were reported in the past 24 hours. Of those new deaths, only five were reported outside Hubei province (3 in Henan, and 2 in Guangdong).

Hundreds of Americans have been flown out of Japan after leaving the quarantined Diamond Princess cruise ship on Sunday night, as a further 70 people onboard tested positive for Covid-19, bringing the total to 355.

As well as separating families and preventing people from returning to work, the ban has prevented about 12,000 Chinese students – or around 41% of all Chinese international students studying in New Zealand – from returning to begin the academic year, the government said.

Chinese foreign students are charged significantly higher fees than domestic students, making them a valuable stream of revenue for tertiary institutions around the country.

The director of Universities New Zealand, Chris Whelan, said the travel ban could potentially cost universities NZ$170m in lost fees, and the situation was “extremely serious”.

“We’re currently discussing the idea of an exemption, so some students may be able to come to New Zealand even if there is a more general travel ban,” Whelan told RNZ. “We would be only doing that with the full support of the Ministry of Health and certainly observing any guidelines that they put around it. There are some challenges but we are hopeful we might be able to do something in that space.”

The prime minister, Jacinda Ardern, told Radio NZ that although discussions were taking place, no decision on a student exemption had been made.

“The first thing we’ve done is say yes, their student visas will be still able to give them entry to the country later on – but universities have indicated to us that they have a particular window ... about April, that’s the time by which they need their international students to start,” Ardern said.

“Public health is our No 1 priority here. There are a couple of things which make any exemptions tricky. Of course ... you’d basically have to be making these individualised decisions for what are thousands of visa holders, and that is quite a logistical exercise.”

Ardern said any students arriving would need to self-quarantine and this could be a complicated logistical exercise, but Whelan said plans had already been made to make any quarantine period as smooth and streamlined as possible.

Whelan said any first-year student who was not able to begin the academic year would likely choose to start their degree elsewhere – meaning the New Zealand university would lose four of five years of fees.

The Chinese consulate in New Zealand has expressed its disapproval of the travel ban and said it should be lifted for all Chinese nationals, who could self-quarantine once they arrived in the country instead. The ban was not in line with WHO recommendations, the consulate said.

So far there have been no confirmed cases of coronavirus in New Zealand, though more than eight people have been tested for the virus, and hundreds remain in quarantine in Auckland after being evacuated from Wuhan, the city at the heart of the outbreak in Hubei province.