The Museum of Fine Arts, Boston will loan to South Korea a 14th-century Buddhist reliquary, following a deal reached Monday that marks a dramatic shift in the US museum’s position on the artifact over the last 15 years.

A day of negotiations at the museum resulted in the Museum of Fine Arts donating the remains of Buddhist masters found after cremation, called “sarira,” while placing on loan the reliquary from the Goryeo Kingdom (918-1392) containing the sarira, according to the Cultural Heritage Administration on Tuesday.

Officials from the state agency and the museum, joined by a monk from the Buddhist sect believed to have once housed the relics, met for the first time in person since 2009 for talks over repatriating the sarira and reliquary as a set. Negotiations had been stalled since then as the museum was willing to return only the sarira.

In accordance with Monday’s agreement, the Museum of Fine Arts, Boston will hand over the sarira to the Jogye Order of Korean Buddhism, whose monk was at the talks in Boston, no later than the Buddha’s Birthday holiday, which falls on May 15 this year. The museum will place the reliquary on loan, though the duration of the loan and when it will make its way to Korea has yet to be made public.

“We will follow through on what we’ve agreed on. … We will continue to build a friendship with the museum,” CHA chief Choi Eung-chon said in a statement, suggesting more discussions would have to take place before details are finalized.

“We just finished discussing the major points and we will have to figure out how we’re going to deliver on what we said we will do next,” said a CHA official with direct knowledge of the matter, declining to elaborate further.

Speculation over the repatriation of the Buddhist relics resurfaced in April last year, when first lady Kim Keon Hee floated the idea during a visit to the museum on the sidelines of President Yoon Suk Yeol’s state visit to the US.

Choi, the CHA chief, acknowledged that was a turning point for the Korean government to reassess the odds of reclaiming the antiques, a process that has largely been in limbo since 2013, when negotiations fell apart over the Korean government’s ultimatum that both the container and the sarira must be returned as a complete set.

Why the museum has changed its long-held position on the issue remains unclear. Museum officials present at Monday’s talks could not be immediately reached for comment.

Boston’s Museum of Fine Arts has long maintained that it legally acquired the silver-gilt Lamaistic pagoda-shaped reliquary from a dealer in 1939, during the late years of Japan’s 1910-45 colonial occupation of the Korean Peninsula.

According to the museum’s website, the container, representative of Korean Buddhist culture in the 14th century, might have come from Hoeamsa, a temple in South Korea, or Hwajangsa, a temple in North Korea.

However, Karen Frascona, the museum’s marketing and communications director, told The Korea Herald ahead of the Monday deal that the description of the object on the website “indicates uncertainty and is based on scholarly hypothesis.”

“There is nothing in its history to indicate theft, looting or coercive transfer,” Frascona added. “We would receive and assess new information as it is presented. Every claim is considered on a case by case basis.”