The international accord signed by London and Washington allows both governments to control visits to the legendary shipwreck.
An agreement struck and ratified by the UK and the US means the wreck of the Titanic should be better protected in future.
Both governments will be able to veto applications to visit the sunken ship and remove artefacts through the power to grant or deny licences. They say this will help preserve the site and enhance respect for the victims.
The new accord now comes into force after being ratified by Washington late last year. The move was due to be confirmed formally by the UK’s Maritime minister Nusrat Ghani during a visit on Tuesday to Belfast, where the liner was designed and built.
"This momentous agreement with the United States to preserve the wreck means it will be treated with the sensitivity and respect owed to the final resting place of more than 1,500 lives," the minister said in a statement.
Since 2012 the RMS Titanic has been protected as a UNESCO cultural heritage site. One company, the RMS Titanic Inc., has had the right to collect artefacts. Over the past 25 years it has brought more than 5,000 objects to the surface, some of which have been auctioned off.
The UK-US agreement strengthens the UNESCO protection, the British government says. It adds that the wreck, lying in international waters, was not previously protected by specific legislation.
Although a visit by divers in 2019 was the first for several years, the ship is said to be in a fragile state as nature gradually reclaims the wreck.
The UK says it intends to work with other North Atlantic states such as Canada and France to increase protection still further.
The RMS Titanic famously broke up and sank five days into its maiden voyage across the Atlantic in April 1912, after hitting an iceberg. The passenger liner, equipped with the latest technology, was carrying some of the world’s richest people as well as poor migrants seeking a new life in the US.
The wreck was not discovered for over 70 years until an expedition in 1985 by explorer Robert Ballard located it intact on the ocean bed, at a depth of almost four kilometres some 350 nautical miles off Canada’s Newfoundland coast.
The discovery spiked interest in the ship, leading to commercialised diving expeditions and James Cameron’s 1997 film “Titanic”.