Alt-right supporter Richard Spencer. Screenshot via YouTube The US Holocaust Memorial Museum on Monday said it is "deeply alarmed at the hateful rhetoric" reported at a white nationalist, alt-right group's meeting last weekend celebrating the election of Donald Trump.

The Washington, DC, conference of the National Policy Institute made headlines after people in attendance reportedly boasted that Trump's victory would further embolden their cause, which is widely seen as pushing a Eurocentric agenda that has targeted minority groups with hate speech.

"The Holocaust did not begin with killing, it began with words," the museum's statement read. "The Museum calls on all American citizens, our religious and civic leaders, and the leadership of all branches of the government to confront racist thinking and divisive hate speech."

Richard Spencer, the man at the center of the Saturday conference and a representative of the National Policy Institute, said he sees the alt-right movement as having a "psychic connection" to Trump. A video posted Monday by The Atlantic showed Spencer leading conference attendees in a chant of, "Hail Trump! Hail our people! Hail victory!" Some attendees appeared to raise their arms in a Nazi-style salute.

Alt-right groups last week took Trump's appointment of Steve Bannon as White House chief strategist as a nod to their cause, and the president-elect took fierce criticism for his choice.

Trump and his representatives have disavowed endorsements from various white nationalist and Neo-Nazi groups, including the Ku Klux Klan. They did so again Monday.

"President-elect Trump has continued to denounce racism of any kind and he [got] elected because he will be a leader for every American," Trump transition team spokesman Brian Lanza said in a statement.

But despite the Trump camp's insistence that it wants nothing to do with the groups, the organizations have often reiterated their praise.