Carnival Cruise Line has outlined plans for a phased resumption of operations in parts of North America this summer with eight ships sailing out of Miami, Port Canaveral and Galveston from 1 August.
However, the line said its pause of operations would be extended in all other North American and Australian markets until August 31.
As part of the plan, from 1 August Carnival Dream, Carnival Freedom and Carnival Vista will sail from Galveston; Carnival Breeze and Carnival Elation will operate out of Port Canaveral and Carnival Horizon, Carnival Magic and Carnival Sensation will cruise from Miami.
All Carnival Spirit Alaskan cruises from Seattle will be cancelled, as well as the Carnival Spirit Vancouver-Honolulu cruise on 25 September and the Honolulu-Brisbane transpacific cruise on 6 October.
Carnival Splendor cruises in Australia from 19 June to 31 August will also be cancelled.
Carnival said impacted guests and their travel agents were being notified by email and offered options to take a future cruise credit and onboard credit package or a full refund.
The line added in a statement: "We are committed to supporting all public health efforts to manage the Covid-19 situation. We are taking a measured approach, focusing our return to service on a select number of homeports where we have more significant operations that are easily accessible by car for the majority of our guests.
"We will use this additional time to continue to engage experts, government officials and stakeholders on additional protocols and procedures to protect the health and safety of our guests, crew and the communities we serve.
"We appreciate the understanding and support of our guests and travel agent partners and look forward to welcoming them on board as the environment for travel and tourism improves."