The cruise companies had previously cancelled all voyages up to May 15.
Clients with affected bookings automatically receive credit for a future cruise worth 125% of the cost of the original trip.
Sailings for Cunard Line's Queen Elizabeth were cancelled up to September 8 as the liner would not have been viable to operate a shorter summer season, the company said.
TUI river cruises have been cancelled until November 25, 2020.
For Coronavirus updates on cruise ship quarantines (infected passengers and crew) and top-pandemic countries (COVID-19 cases and deaths, daily updated statistics) see at CruiseMapper's Norovirus page.