The governors of New York, New Jersey and Connecticut issued a travel advisory saying visitors from US states with accelerating Covid-19 infection rates must quarantine for 14 days, AFP reported.

The advisory effective at midnight applies to travellers from Alabama, Arkansas, Arizona, Florida, South Carolina, North Carolina, Washington, Utah and Texas, New York's governor Andrew Cuomo said.

The announcement comes as Covid-19 numbers in New York — once the epicentre of the global pandemic, where more than 20,000 people have succumbed to the disease — trend downward while infection rates spike elsewhere.