Chancellor Angela Merkel and Turkish Foreign Minister Mevlut Cavusoglu will attend ceremonies along with Mevlude Genc, 75, who lost two daughters, two granddaughters and a niece in the 1993 house fire in the town of Solingen.
Despite her huge personal loss in one of post-war Germany's most notorious racist hate crimes, which sparked days of rioting, Genc went on to call for reconciliation, for which she later received Germany's highest civilian honour.
President Frank-Walter Steinmeier, after meeting Genc last Friday, praised her “as a role model for everyone who fights against discrimination, racism and violence” and warned that “the memory of this cruel act must not fade”.
Germany has struggled with a new upsurge of racist attacks and far-right activism, including the entry into parliament of the Alternative for Germany (AfD) party, after an influx of more than one million asylum seekers since 2015.
Turkey's foreign ministry Monday voiced concern that “racism, xenophobia and Islamophobia are on the rise” again in the EU country and called on politicians and media there to “use prudent language”.
AfD co-leader Alice Weidel this month received a formal rebuke from the parliamentary speaker for describing immigrants as “headscarf girls, welfare-claiming, knife-wielding men and other good-for-nothings”.
While both Germany and Turkey will voice their common sorrow over the tragic deaths, tensions linger between the governments of Merkel and President Recep Tayyip Erdogan, who faces elections on June 24th.
Berlin has barred Turkish politicians from campaigning in the country home to three million ethnic Turks — the largest diaspora abroad — some 1.4 million of whom can vote in their ancestral homeland.
Several German politicians have cautioned that Cavusoglu must not use the memorial event to campaign for Erdogan's AKP party or deepen divisions in the Turkish-German community.
After Erdogan last year slammed Germany's “Nazi-style” ban on Turkish campaign speeches, Berlin imposed a blanket ban on political events by non-EU politicians within three months of elections in their countries.
Police at a Kurdish rally in Cologne last Saturday prohibited two former lawmakers of Turkey's opposition HDP party from addressing the crowd.
German Foreign Minister Heiko Maas on Sunday reiterated Berlin's position, while stressing that Cavusoglu's speech would “not constitute election campaigning but commemorate the victims of this terrible attack”.
'Remembrance, not disputes'
The issue is highly sensitive, given the horrific nature of the crime a quarter-century ago, and in view of both countries' recent efforts to overcome a rift that deepened especially following Erdogan's crackdown after a failed 2016 coup.
The deadly Solingen blaze was set by four males, aged 16 to 23, from the far-right skinhead subculture that flared in the early 1990s amid an influx of eastern European asylum seekers.
Two women and three girls died, the youngest just four years old, and 14 others including several children suffered injuries.
All perpetrators received maximum jail terms, of 15 years for the adult offenders, and all were released from prison years ago, some early because of good behaviour.
The space where the charred remains of the Genc family house once stood is now a vacant lot where five chestnut trees have been planted to honour the victims.
Merkel, the two foreign ministers and victims' relatives will from 1000 GMT attend a ceremony at the North Rhine-Westphalia state chancellery in Düsseldorf.
From 1400 GMT, Cavusoglu and Maas will join a ceremony in Solingen organized by the town hall, the Genc family, and local Muslim, Christian and civic organisations.
State premier Armin Laschet criticized as “shameful” that the state parliament will not also hold a ceremony in which Cavusoglu could have spoken, saying the focus must be on “remembrance, not political disputes”.
Some 400 leftist activists marched in Solingen last Saturday, warning against Germany's newly emboldened far-right.
“Back then they spoke of a 'flood of asylum seekers', today they speak of a 'refugee wave', an equally stupid term,” demonstrator Robin Rau told public broadcaster WDR.
“When you look at how the mood was back then and how it is turning again now, I believe it's important to rally in the streets and to speak out against it.”