There are so few Christians left in Iraq that just one more wave of persecution could wipe them out for good, a church leader has warned.

The Chaldean Catholic Archbishop of Basra, Habib Nafali, said Christianity's 2,000-year history in Iraq could come to an end if Christians are subjected to more persecution.

Speaking to the Catholic News Service, Archbishop Nafali blamed years of violence against Christians for the exodus. 

He said the scale of the violence against Christians was tantamount to genocide and that the Islamic State continued to pose a threat.

While military campaigns have pushed the Islamic State back in the past year, it has not been completely defeated and he fears that Christians are still at risk.

'We have seen with our own eyes how they attack Christians,' he said.

The Archbishop said Christians had been the targets of 'systematic violence' designed to 'destroy their language, to break up their families and push them to leave Iraq'.

He estimated the number of Christians still in Iraq at around a quarter of a million, a huge drop from the 1.5 million living there in 2003.

While many have sought refuge in the UK, US and other countries, the Archbishop said Christian refugees were put off returning because in addition to the threat of violence from extremists, many struggle to get by because of the discrimination they face in the area of employment.

So many Christians have left the country that he now fears any more violence will push the last few remaining away for good.

'Another wave of persecution will be the end of Christianity after 2,000 years,' he said.

'There is a global game, and the peaceful people - the minorities - in the end will be the ones who are destroyed,' he said.

He added, 'If this is not genocide, then what is genocide?'