A group of kidnapped Christians in Syria might be closer to freedom after ISIS lowered its demands for their release.

The ransom price for 230 Assyrian believers, who were captured by ISIS in February, has been significantly lowered after it became clear their community could not afford ISIS' demands.

"In the first attempted contact through intermediaries there was talk of an exorbitant request, amounting to $23million to free the Christian prisoners," Syrian Catholic Archbishop Jacques Behnan Hindo told Fides News Agency. This amounted to about $100,000 per hostage.

ISIS is now demanding much less, Hindo added. The difficulty is no longer money, he explained, but the logistics of organising their freedom.

"Now the biggest obstacle regarding the release of our Assyrian brothers is no longer money, but the difficulty of how to organize the phase of liberation," the Catholic Archbishop said.

"Four buses would be needed to release the hostages from the place of their seizure to get them back to Hassaké and avoid any danger of attacks. In any case, it would be a delicate operation, which in some way should be agreed with the Syrian army forces and Kurdish militias, so that everything proceeds smoothly."

It is suspected the Assyrians, who were kidnapped in raids on their villages in the Khabur river valley, are held in ISIS' al-Shaddadi stronghold.

As many as 15,000 Assyrian Christian families are facing danger from ISIS and the ongoing civil war in Syria, one source estimated.