Image copyright Getty Images Image caption Jonathan Greenblatt, CEO of the ADL, urged non-Muslims to "stand with our fellow Americans"

The Jewish head of the Anti-Defamation League (ADL), an anti-bigotry group, has vowed to register as a Muslim if Donald Trump creates a database of Muslim Americans.

The idea of a Muslim database arose in November 2015, when Mr Trump told a reporter he would "certainly implement that. Absolutely".

Jonathan Greenblatt, CEO of the ADL, said: "If one day Muslim Americans will be forced to register their identities, then that is the day that this proud Jew will register as a Muslim".

His comments came at the group's Never Is Now conference on anti-Semitism, held in New York.

Image copyright Twitter / ADL Image caption The ADL shared Mr Greenblatt's comments on Twitter, where many praised him for taking a stand

"We must stand with our fellow Americans who may be singled out for how they look, where they're from, who they love or how they pray," Mr Greenblatt said.

The ADL chief, who previously served in the White House as special assistant to President Barack Obama, told BBC News: "The bottom line here is - we in the Jewish community know what it is when you apply a litmus test based on faith - when you identify people and tag them based on faith...

"When you take one group and make all of them suspect. I feel we have more obligations to speak out."

Mr Trump's position on the proposed Muslim register is presently unclear.

In a statement on Thursday, a spokesman for the Trump transition team appeared to row back from his comments last year, saying Mr Trump had "never advocated for any registry or system that tracks individuals based on their religion, and to imply otherwise is completely false".

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Jason Miller was responding to new reports that Mr Trump's team was considering a database for US immigrants from Muslim countries.

Mr Greenblatt's pledge to register as Muslim struck a chord with many people on social media, who took up the hashtag #NeverIsNow.

Cornell W Brooks, president of African-American civil rights group the National Association for the Advancement of Colored People (NAACP), was among those to second the pledge.

"As a proud Christian & a card-carrying member of the @NAACP, I'll also register as a Muslim right behind @JGreenblattADL," he wrote.

Media playback is unsupported on your device Media caption Election 2016: Muslim-Americans 'grieving' after Trump win

"Never is now" refers to the "never again" vow made by Jews after World War Two, when they promised never to stay silent in the face of persecution.

According to an FBI report released this week, hate crimes on the basis of religion increased 23% between 2014 and 2015. This included a rise in reported anti-Jewish crimes, and a significant increase in anti-Muslim hate crimes.

The Southern Poverty Law Center, a non-profit group based in Alabama, reported 437 separate incidents of intimidation between the election on 8 November and 14 November, targeting ethnic minorities, Muslims, immigrants, women, and the LGBT community.

US Attorney General Loretta Lynch said the justice department was investigating whether recent reports of harassment, for instance at schools and churches, violated federal hate crime and other civil rights laws.

"Many Americans are concerned by a spate of recent news reports about alleged hate crimes and harassment," Ms Lynch said.

She urged the public to keep reporting such incidents, "so that our career investigators and prosecutors can take action to defend your rights".