Greenland's parliamentary election results showed a decisive victory for a left-wing environmentalist party opposed to a controversial mining project.

Inuit Ataqatigiit (IA) won 36.6% of the vote, beating out Siumut, a social democratic party that has dominated politics in the Danish territory since it gained autonomy in 1979.

"The people have spoken," IA leader Mute Egede said in a post to Facebook early Wednesday. "Your trust commits us to a great responsibility which we will strive to meet."

The fate of a rare-earth and uranium mining project in the country's south was at the center of Tuesday's election, which pitted those in favor of more rapid development against those who want more measures to protect the island's fragile Arctic environment.

IA had lobbied against the Kvanefjeld project, which had been given tentative approval by Prime Minister Kim Kielsen's Siumut party government.

This is only the second time the party has dethroned Siumut as the largest party in Greenland, a vast territory with a population of just 56,000 people, 41,000 of whom are eligible to vote.

IA is expected to take 12 of the 31 seats in the local parliament Inatsisartut, up from eight in the outgoing body.

Internal strife in Siumut has weakened the organization in recent years. It received 29.4% of the vote, which was two percentage points higher than its results in the 2018 election.

Party leader Erik Jensen has said that the mine would be "hugely important for Greenland's economy," helping to diversify revenue sources. Such a plan is critical if the island is to achieve full independence from Copenhagen in the future.

In 2019, then-President Donald Trump proposed purchasing Greenland from Denmark, comparing the transaction to "a large real estate deal." The plan, however, was rejected both in Greenland and Denmark.

Mette Frederiksen, the Danish Prime Minister, said unequivocally: "Greenland is not for sale."