The spike in cases comes as Victorian Health Minister Jenny Mikakos insists medical professionals have her support, despite not apologising to an infected doctor whom she chided for going to work when he felt unwell.

Authorities confirmed on Monday two of the most recent COVID-19 cases are returned travellers from the United States, while another is from Iran.

Premier Daniel Andrews has called a special meeting of his cabinet's security and emergency management committee on Tuesday morning to discuss the state's coronavirus preparations.

Victoria has not yet had a coronavirus case transmitted locally, but Ms Mikakos expects it will.

"This is likely to occur and is just a matter of time," Ms Mikakos told reporters on Monday.

The most serious of the latest cases is a woman in her 50s who returned from Tehran via Kuala Lumpar on flight MH0149, arriving on Friday.

She became unwell in Tehran on February 18 with a cough, fever and shortness of breath, and upon her arrival to Australia was immediately driven to hospital by a relative and treated for pneumonia.

The woman remains in hospital in isolation and is in a stable condition.

A man and woman who travelled from the US are recovering in home isolation.

The man, aged in his 50s, was on flight UA60 on February 29 and has a very mild illness.

It is not clear if he contracted coronavirus from the flight or while overseas.

Before he was diagnosed, he visited Wine by Sam at Seymour on March 3 for a winery tour and lunch, then attended Cinema Nova at Carlton on Thursday from 7.30pm to 10.30pm for a private screening of The Amber Light.

The second traveller from America is a woman in her 20s who arrived from Colorado on flight QF94 from Los Angeles to Melbourne on Friday.

The cases come after Dr Chris Higgins, the father of singer Missy Higgins, was the 11th Victorian to test positive for the virus, after treating more than 70 patients while having what he thought was a mild cold.

Ms Mikakos said on Saturday she was flabbergasted a doctor with flu-like symptoms had continued to treat patients.

Her comments caused the Australian Medical Association and Dr Higgins to see red and demand an apology, given the GP had followed the official clinical health guidelines.

The minister says she "won't make any apology for putting the public health of Victorians first".

"I understand that this may be distressing for the individuals involved, and I'm sorry if they feel distressed, but we have to absolutely focus on the task at hand, and that is making sure that Victorians get access to timely, reliable information," she told reporters.

But she said medical professions can rest assured she "absolutely have their back(s)".

Australian Associated Press