The Archbishop of Canterbury has promised that the Church of England will take antisemitism seriously and apologised for an incident involving an Anglican priest this year.

In his first major address to a Jewish audience, Justin Welby told the Board of Deputies' annual dinner in London on Tuesday that there would be no repeat of an earlier episode where he had personally failed to protest.

The head of the Anglican Church, who took office two years ago, said that Jewish communities should feel "utterly unafraid about the future. And everything that imperils that is something the Church among others is called to stand against".

But the church contained a wide variety of views and "we will continue to fall down on this from time to time", he said.

Earlier this year an ordained priest had been responsible for an "atrocious use of language" around the time that the archbishop had hosted the launch of a report by the All-Party Parliamentary Group Against Antisemitism.

While he hoped that the church had dealt effectively with the incident, he said: "I want to say I am sorry that happened, to apologise for that."

Although he did not go into details, Archbishop Welby was understood to be referring to a social media post from Stephen Sizer, who linked to an article which suggested that Israel had been responsible for the 9/11 attacks.

The Surrey vicar was banned from commenting on the Middle East and warned a repetition could cost him his job.

Archbishop Welby - whose paternal grandfather was Jewish - pledged that "we will take antisemitism seriously within the Church. I have made in the past one serious mistake on that, failing to stand up and protest about something when I should have done - it was about three years ago. And I will not make that mistake again. That at least I can promise".

He also called for greater efforts at inter-religious reconciliation following the violent attacks on Jewish and other communities in Europe, the Middle East and Africa over the past "shocking 12 months".

It was not enough for religious leaders to issue "bland statements of anaemic intent", he said.