As a visible sign of Brexit, a new flagship is to represent the United Kingdom on the world's oceans in the future.
The ship succeeds the royal yacht "Britannia", which was decommissioned in 1997 and has since been moored as a museum in Scotland.
Construction of the new ship is scheduled to begin in 2022.
Trade fairs, summit meetings and diplomatic talks will take place there, as Prime Minister Boris Johnson announced on Sunday night.
A name has not yet been chosen.
The ship will "reflect Britain's burgeoning status as a large, independent maritime trading nation," said Johnson.
It is "a clear and strong symbol of our commitment to be an active player on the world stage".
The cost will be around 200 million pounds (233 million euros), the ship will be in operation for around 30 years.
Conservative MPs urge it to be named after Prince Philip, Queen Elizabeth II's recently deceased husband.
Johnson had repeatedly emphasized that after Brexit, Great Britain could now again decide on its own trade policy.
In addition, the government is arming the military and wants to become the leading naval power after the United States.
However, important trade talks are currently stalling, for example with the USA, but also with Norway and Australia.