The governor of New York on Saturday announced a state of emergency as the coronavirus continued to spread in the northeastern state, with 21 new cases.

A total of 76 people have so far tested positive for the virus, Governor Andrew Cuomo told reporters in the state capital of Albany. Ten of those affected have been hospitalized.

The state of emergency, he said, "allows expedited purchasing and expedited hiring, which are the things we need now."

Cuomo said the state would probably be spending $30 million a week to fight the Covid-19 disease.

The authorities are now "aggressively testing" 24 hours a day, he said. "We want to find positives... (then) we can put them in an isolated situation."

"That's the point of the exercise," Cuomo added. "You isolate them and you slow the spread."

Fifty-seven of those infected have links to the Orthodox Jewish community in New Rochelle, a city in Westchester County 20 miles (32 kilometers) northwest of New York City.

"Westchester is an obvious problem," the governor said. "We talk about contagion in clusters; clusters tend to infect more and more people."

In an effort to slow the spread of the virus, retirement homes and nursing facilities in the New Rochelle area are banning visits by outsiders.

"We are (being) hypercautious," Cuomo said.

He said the quarantine period of 14 days for infected people might be extended.

The governor also warned store owners against exploiting the situation by inflating their prices for virus-related products.

"We have reports of stores selling hand sanitizer for $80 a bottle," he said.

"It's not worth it to the store owner," added Cuomo, a former New York attorney general. "You can lose your license... It's illegal."

The United States has seen more than 200 cases of the novel coronavirus, including 19 deaths, according to official tallies compiled by AFP.

Sixteen of the deaths have been linked to a retirement home in Washington state, in the northwestern corner of the country.

© Agence France-Presse