WASHINGTON (Nexstar) — Six hundred stolen Native American ancestral remains and artifacts, held at a museum overseas, have officially been returned to U.S. soil.

The U.S. has been trying for more than seven decades to secure the artifacts and remains from the National Museum of Finland to return to tribes of the Mesa Verde Region.

President Donald Trump was joined by U.S. Ambassador of Finland Robert Pence and Native American leaders for the announcement.

“How big is today? It’s huge,” said Pence.

In 1891, a young Finnish professor traveled to Mesa Verde in Colorado to study the cliff dwellings. A few years later, he returned to Finland taking the remains and artifacts with him. Since then, they’ve been sitting in the Finland museum.

“We took the remains back on Saturday from Helsinki all the way to Mesa Verde,” Pence said.

It took 70 years of negotiations between U.S. and Finland before Trump and the president of Finland struck a deal last October.

“They bonded very quickly, and everyone agreed this was the time,” Pence said.

Assistant Secretary Of Indian Affairs Tara Sweeney says it was a solemn occasion.

“This is very significant to Native American populations regardless of where you are in the country, and it is especially special for these tribes to have these culturally significant items,” Sweeney said.

Pence says there are still remains and other cultural artifacts in the Finnish museum, and the White House is working to bring them back, too.