A week before chancellor Angela Merkel welcomes G20 leaders to Hamburg, the German leader is gearing up for high-level showdown with United States president Donald Trump and Turkey's Recep Tayyip Erdogan.
German politicians' statements over President Erdoğan's potential rally in the country were unacceptable, Turkish Presidential Spokesperson İbrahim Kalın said on June 29, describing them as "provocative and malevolent".
Gabriel described the proposal as "not a good idea", saying that given the tensions between Germany and Turkey "the political climate" is not ripe for Erdogan to hold a political rally addressing Turks.
While German authorities rejected the requested meeting with Turkish citizens on the sidelines of the G20, Gabriel noted that events could be held inside the Turkish embassy or consulates in Germany.
In swift response to German politicians' statements, Turkish Foreign Ministry said their remarks were made upon domestic policy considerations and were "regrettable".
Germany's foreign minister says Berlin will tell Ankara that a rally by Turkish President Recep Tayyip Erdogan when he visits Germany for the Group of 20 summit is "not possible".
The spokesman also accused EU officials of double standards, apparently referring to former European Parliament President Martin Schulz, who called the Turkish president and his Russian and American counterparts, Vladimir Putin and Donald Trump, "autocratic rulers".
Meanwhile, a number of venues located in the North Rhine-Westphalia region have refused to host Erdogan, according to German media reports.
German officials have repeatedly said they do not want internal conflicts in Turkey spilling onto German soil, where some three million people of Turkish origin live.
German local authorities' banning of campaign rallies by Turkish ministers earlier this year contributed to tensions between the two countries, which were also inflamed by other issues like Turkey's jailing of two German journalists.
Merkel told the German parliament Thursday that "protectionism can not be a solution" to the world's problems.
In February, Turkey arrested a Turkish-German Die Welt reporter Deniz Yücel on charges of inciting hatred and terrorist propaganda.
Since then, however, German politicians have become far more critical of Erdogan's governance, in particular condemning his crackdown following a failed coup attempt in July 2016.
The refusal prompted German parliament to decide to move their military installations from the key Incirlik airbase in Turkey.