President Donald Trump has tweeted that four major cruise ship companies have agreed to suspend trips from the US for 30 days, effective at midnight.

Mr Trump said that Carnival, Royal Caribbean, Norwegian and MSC Cruises all agreed to the suspensions.

He said the cruise line industry is a “great and important industry – it will be kept that way!”

The US State Department advised on Sunday against any travel on cruise ships, particularly for those with underlying health conditions.

The advisory said the CDC has noted an “increased risk of infection of Covid-19 in a cruise ship environment.”

Cruise industry leaders met over the weekend with Florida governor Ron DeSantis and Vice President Mike Pence and were asked to devise and fund ways to transport any passengers found to carry the virus.

Cruise line heads agreed to enhance entry and exit screenings and establish shipboard testing, along with new quarantine standards.

Some of the new protocols were expected to start taking effect early this week.