The German government said it is repulsed by the Nazi-style salutes at a far-right event in Washington this week. Trump has disavowed links to the innocuously named National Policy Institute (NPI), but doubts remain.
"Whenever we see videos from anywhere showing people raising their hand to do Hitler salutes we are repulsed," government spokesman Steffen Seibert said on Wednesday, adding that Germany has "great faith in American civil society, media and politics to address such bad developments, such terrible events."
The Nazi salute is illegal in Germany today, as are a range of actions considered hate crimes, including "incitement of the people" through hatred, denying or downplaying the Holocaust or Nazi crimes, or violating the dignity of the Nazis' victims.
Meanwhile, the news agency Reuters reported from an anonymous source that German Chancellor Angela Merkel's government is worried that white supremacists in the US are being emboldened by the election of Donald Trump.
"I don't think this is Trump's ideology because he seems to be largely free of ideology. But these people are riding on his coattails. We are watching this very closely," the official told Reuters, requesting anonymity.
Protests, outrage following video showing Nazi-style salutes, slogans
A video published by "The Atlantic" showed participants at an event on Saturday raising their arms in salute during a speech by Richard Spencer, head of the white-nationalist National Policy Institute.
"Hail Trump, hail our people, hail victory!" Spencer shouts at one point as some members of the audience raise their arms in the Nazi salute.
The gathering on Saturday drew protesters who blocked traffic around the Ronald Reagan Building, a federally owned conference centre in downtown Washington for both public and private use where the event took place.
Trump on Tuesday denounced the so-called alt-right, a spokesman for the Trump-Pence transition team saying on Monday that Trump "continued to denounce racism of any kind" and was elected to be "a leader for every American."
Meanwhile on Wednesday, Yair Lapid - a member of the foreign affairs and defense committee in the Israeli Knesset - called the video "sickening" and "intolerable."
"One of the greatest mistakes humanity ever made was a failure to recognize the danger of fascism early enough and tackle it head on," said Lapid. "We cannot let history repeat itself."
David Keyes, the foreign media spokesman for the Prime Minister Benjamin Netanyahu, said in response to a Reuters query about the Washington meeting: "Prime Minister Netanyahu condemns anti-Semitism everywhere and appreciates President-elect Trump's denunciation of all forms of racism."
jbh/kl (AP, AFP, Reuters)