A passenger wearing a mask stands on the desk of the cruise ship Diamond Princess, as the vessel's passengers continue to be tested for coronavirus, at Daikoku Pier Cruise Terminal in Yokohama, south of Tokyo, Japan, on February 13, 2020.
The ship, Norwegian Jewel, was in New Zealand earlier this month for a 10-day tour around NZ before arriving in Sydney today.
When the cruise ship was sailing from Auckland to Sydney, some guests had a stomach-related illness.
A local official from Quang Ninh Province said that "not allowing passengers" on the vessel to "visit the shore is one of several temporary solutions to prevent the disease from invading", according to state media.
A spokesperson for Norwegian Cruise Line said the vessel was in operation and all guests were in good health.More news: Owner of Lexington Herald-Leader files for bankruptcy protection
The German operator belongs to the same family as Princess Cruises which is running the ill-fated Diamond Princess cruise.
Marine tracking website Marinetraffic.com said the AIDAVita is docked off the coast of Thailand, near Bangkok, as of Friday.
However, no passengers had any respiratory-related illnesses.
A spokesperson for Norwegian Cruise Line said no guests have had any respiratory illnesses on board Norwegian Jewel.
'Still, the port has proven to be unreasonable during this process and late last night informed us that despite previously approving our calls and despite the actions we've taken to accommodate their new protocols, that they are denying our upcoming calls, ' he said.More news: Ubisoft Reveals A VR Escape Room From Prince of Persia
Norwegian Cruise Line has barred all Chinese, Hong Kong and Macau passport holders from its ships regardless of residency.
It was not clear which port he was referring to and Vietnamese port authorities have declined to comment.
"Before anyone can disembark the ship, they are going on board, screening those passengers and if all clear, everyone will come off the ship", the spokesperson said.
In Yokohama, thousands of people on the Diamond Princess face five more days in quarantine with the number of confirmed virus cases now at 218.
A spokeswoman for the Ministry of Health said coronavirus or COVID-19 was a notifiable infectious disease in New Zealand.More news: Hubei Adds 4,823 Cases; China Virus Death Toll at 1,483