(CNN)Germany's president Frank-Walter Steinmeier has warned of the fractures in its society -- highlighted by the electoral success of the far-right party Alternative for Germany (AfD) -- on the nation's Day of German Unity.
German president: New walls have gone up
On October 3, a national holiday, Germans mark the reunification of East and West Germany in 1990, following the fall of the Berlin Wall the previous year.
"It is right that we celebrate this day, like every year," Steinmeier told a large gathering of politicians and citizens in Mainz, western Germany. "But something is different this year ... we must not go on as if nothing has happened."
"Other walls have gone up," he said, "less visible and without barbed wire and death strips, but still walls that stand in the way of our collective 'we.'"
Steinmeier spoke of walls between cities and rural areas, between rich and poor, old and young, and online and offline communities.
They are "walls of alienation, frustration or anger" and behind those walls there is "deep mistrust of democracy and its representatives," Steinmeier said.
Without mentioning the AfD by name, Steinmeier warned that Germany's progress since 1990, becoming a democratic, peaceful and strong country at the heart of Europe, could be lost if politicians and ordinary Germans do not work together to fight the party's far-right ideology and to respond to the concerns of its supporters.
The AfD -- originally an anti-European Union and anti-euro party that has since turned its focus to immigration and Islam -- won 12.6% of the vote in the elections on September 24 and became the third largest party in the German parliament, according to preliminary results.
Like many other far-right parties across Europe, the AfD has branded itself as an anti-establishment party of protest, appealing to those citizens previously disillusioned by or uninterested in politics.
And their strategy seemed to work: nearly 700,000 votes for the AfD came from former non-voters, according to preliminary data from political polling firm Infratest Dimap.
Support for the AfD was particularly high in the former East Germany, where 21.5% of votes went to the far-right party, according to Infratest Dimap.
Speaking to CNN on the night of the election results, Jasna Zajcek, an expert on rise of the far right in eastern Germany, said one of the reasons the AfD had performed better than expected was that many voters in the east do not feel integrated into modern Germany.
She said these voters feel they still suffer from the loss of the more socialist state system that the former East Germany once provided.
Those voters don't understand why economic benefits are "thrown" at migrants while they suffer from high unemployment, small pensions and drug and alcohol problems, Zajcek added.
Steinmeier addressed this issue in his speech Tuesday, saying many Germans from the former East no longer feel at home in their own country, and question if anyone is looking out for them.
"This desire for a home, a homeland -- we mustn't leave that to the nationalists," said Steinmeier.
"There must never be a route back to nationalism," he insisted, a statement that was met with a sustained ovation.
Steinmeier did, however, suggest Germany should consider stricter immigration controls in what can be seen as a bid to draw AfD voters back to the mainstream parties.
Germany should give asylum to those who are eligible, he said, but must also consider "which forms of and how much immigration we want ... and need."
"Migration should be controlled according to our requirements," he continued, insisting that people who come to Germany must learn the language and abide by the country's laws and values. "That cannot be up for discussion."