Germany's far right has achieved its most significant regional electoral triumph since World War II, as the Alternative for Germany, or AfD, party won a major victory in the eastern state of Thuringia, a result it has hailed as a "historic success".

The victory on Sunday for the anti-immigrant AfD represents a setback for Germany's political center, particularly for Chancellor Olaf Scholz's ruling coalition of three parties, which suffered losses in the vote.

"The results for the AfD in Saxony and Thuringia are worrying," Scholz said in a statement to Reuters.

"Our country cannot and must not get used to this. The AfD is damaging Germany. It is weakening the economy, dividing society and ruining our country's reputation."

The AfD, founded in 2013, won 32.8 percent of the vote in Thuringia, outperforming the mainstream center-right Christian Democratic Union, which secured 23.6 percent.

In the neighboring state of Saxony, the AfD finished a close second, by just half a percentage point, to the Christian Democratic Union, which leads the national opposition.

A new populist-left party, the Sahra Wagenknecht Alliance, secured third position in both states.

Dealing a blow to Scholz

The far right's success deals a blow to Scholz's coalition just a year before the federal election, with his Social Democratic Party and coalition partners, the Greens and liberal Free Democrats, all performing poorly in Sunday's vote.

Despite the AfD achieving a historic first by becoming the strongest party in a state election, it is almost certain to be excluded from power as all other rival parties have so far ruled out any direct cooperation with it, Deutsche Welle reported.

The AfD is led in Thuringia by Bjorn Hocke, regarded as one of the party's most extreme figures.

Hocke has faced legal consequences twice this year alone for employing prohibited Nazi slogans during his campaign events and is known for his frequent use of Nazilike rhetoric.

Speaking after the vote, Hocke said he felt "a great, great deal of pride" and told public broadcaster ARD that his party would analyze the results before approaching potential coalition partners.

When questioned about his party's classification as extremist, he said: "Please stop stigmatizing me. We are the number one party in Thuringia ...You don't want to classify one-third of the voters in Thuringia as right-wing extremists."

The AfD, campaigning on a central demand for drastic changes in immigration policy, ran on a platform calling for the mass deportation of refugees from Germany.