Canada and Britain have reached a formal agreement on ownership of the Franklin expedition wreckage which allows the U.K. to keep all 65 artifacts already discovered by Parks Canada's diving teams.

The wrecks of HMS Erebus and HMS Terror, along with any yet-to-be-discovered artifacts, will be formally transferred to Canada and the Inuit Heritage Trust. Canada will not be seeking compensation from Britain for the recovery and restoration the Franklin relics, which cost millions of dollars.

During a news conference at the Museum of History in Gatineau, Que., Environment Minister Catherine McKenna expressed gratitude for the "generous" gift.

"It's an exceptional step that the government of the U.K. has taken. It's a recognition of the strong relationship between the two countries," she said.

The agreement ensures the historic treasures will be available to Inuit, the public and researchers in Canada and the U.K.

The 65 items recovered are fragments of the doomed Franklin Expedition's story — everything from pieces of the ships themselves to shards of pottery. British High Commissioner to Canada Susan le Jeune d'Allegeershecque said it's important to keep some of the historical items in U.K.'s custody.

"This is part of our history too," she said at the news conference. "And the important thing was to have a representative selection of the artifacts so that people in the U.K. would also be able to remain in touch with this story and understand our shared history.

"Because it's not just a Canadian story, it's not an Inuit story. It's a story that affects us all."

Torsten Diesel of the Inuit Heritage Trust (left), British High Commissioner to Canada Susan le Jeune d'Allegeershecque (centre) and Environment Minister Catherine McKenna sign an agreement to formally transfer ownership of the Franklin wrecks from the U.K. to Canada at a ceremony in Gatineau, Que. today. (Max Paris/CBC News)

Marc-André Bernier, manager of underwater archeology for Parks Canada, said the next step is to explore and excavate the ships, which are well-preserved.

He said he anticipates "amazing surprises," and hopes to find written documents that could shed new light on the historic journey.

"It's also the human story behind every object that we find," Bernier said. "We can talk about people, some of the crew members, who were there who lost their lives trying to find the Northwest Passage and our hope is to bring those back to life."

A news release from U.K. Defence Secretary Gavin Williamson called it a "historic milestone" in the long-standing cooperation between both countries on the issue.

"We have deep historic links with Canada and this gift is testament to our prospering relationship," he said. "The story behind these vessels is both fascinating and incredibly important to the history of both our nations. The U.K. joined forces with the Canadian government and Inuit population to search for these ships for 172 years and I'm delighted they will now be protected for future generations."

Both sides announced in October 2017 that ownership of the mid-19th century ships HMS Erebus and HMS Terror and their contents, legally owned by Britain's Royal Navy under international law, would be formally transferred to Canada, but details of a formal agreement had not been worked out.

Officials have been in negotiations since May 2016.

HMS Erebus and HMS Terror, shown in the Illustrated London News published on May 24, 1845, left England that year under the command of Sir John Franklin and in the search of the Northwest Passage. (Illustrated London News/Getty Images)

Talks were hampered, in part, by the sensitive question of which artifacts the British would keep, and how Canada would be compensated for their recovery and restoration.

Canada and Britain signed a non-binding deal in 1997 — before the wrecks were located — that confirmed the Royal Navy's ownership but committed Britain to transferring ownership to Canada eventually.

Artifacts of 'outstanding significance'

An exception was made for any artifacts of "outstanding significance" to the Royal Navy, which Britain would keep after paying Canada compensation.

A Parks Canada document obtained by CBC News under the Access to Information Act said those costs would be difficult to quantify.

The Liberal government already has committed to eventually sharing ownership, and management, of the Franklin wrecks and artifacts with the Inuit Heritage Trust, which represents Inuit claims to the historic finds.

Protected historic sites

The government of Nunavut has also laid claim to ownership of the Franklin ships and artifacts.

Nunavut was able to exercise some control over the underwater archeological site where HMS Terror was found — in Terror Bay, off King William Island — because Parks Canada divers needed permits from the government in Iqaluit to investigate the sunken wreck.

The federal cabinet later declared a 57.8 square-kilometre area around HMS Terror part of a protected National Historic Site, which effectively removed it from Nunavut's jurisdiction and gave the wreck legal protection from souvenir hunters.

The seabed wreck of HMS Erebus, discovered further south in 2014, was given such federal protected status in 2015.

The Royal Navy mounted the 1845 expedition to find a northwest passage under Sir John Franklin. All crew members died after the two ships were trapped by ice, though their exact fate has remained a mystery.