Organisers of a Spanish reggae festival on Wednesday apologised to a Jewish American singer and reinvited him to perform, after previously cancelling his concert for failing to clarify his position on Palestine.

The decision by the Rototom SunSplash festival to pull Matisyahu, who fuses reggae and hip-hop with Jewish influences, from its line-up was criticised by Jewish groups, the Spanish government and the US and Israeli embassies in Spain.

The 36-year-old was originally set to perform on Saturday on the last day of the week-long festival held each year in Benicassim, eastern Spain.

But a local branch of the pro-Palestinian Boycott, Divestment and Sanctions (BDS) movement campaigned against the performance, accusing Matisyahu of being anti-Palestinian and a "Zionist" who supports the practice of "apartheid and ethnic cleansing."

Festival organisers then asked the singer to declare if he was in favour of a Palestinian state, and when they got no reply cancelled his show.

"Rototom SunSplash would like to publicly apologise to Matisyahu for having cancelled his concert and invite him to perform at the festival next Saturday August 22, as was initially programmed in the lineup," organisers said in a statement.

"Rototom SunSplash admits that it made a mistake, due to... the campaign of pressure, coercion and threats employed by the BDS Pais Valencia which made it think that the normal functioning of the festival could be threatened."

Matisyahu -- whose real name is Matthew Miller -- has appeared on stage wearing traditional Orthodox Jewish clothing, although for his latest album he shed his beard and ultra-Orthodox trappings.

On his Facebook page he called the decision to cancel his show "appalling," saying his music "speaks for itself, and I do not insert politics into my music."

"No artist deserves to be put in such a situation simply to perform his or her art. Regardless of race, creed, country, cultural background, etc, my goal is to play music for all people."

In its statement Rototom SunSplash said it "rejects anti-Semitism and any form of discrimination towards the Jewish community."