CDC will follow up with cruise ships when an investigation is required as ships begin to sail with passengers on simulated or restricted voyages under the agency's Temporary Extension & Modification of Framework for Conditional Sailing Order, said the agency.

While cruising will always pose some risk of Covid-19 transmission, CDC is committed to working with cruise ship operators to ensure that cruise ship passenger operations are conducted in a way that reduces the risk of Covid-19 transmission among crew members, passengers and port personnel, the agency added on its website.

Covid-19 cases are surging to record high again as the Omicron variant continues to drive extremely high infection levels, Xinhua news agency reported.

The country registered a grim new record of over 510,000 daily Covid-19 cases on Monday, according to data of Johns Hopkins University.