Militants from the extremist Islamic State in Iraq and the Levant (ISIL) have made dramatic gains in Iraq, prompting US President Barack Obama to order air strikes to halt their advance and air drops to help tens of thousands of fleeing civilians.

Experts from the 15-nation council met Monday to discuss the measure proposed by Britain with a view to adopting a strongly-worded text this week, sources said.

An early draft of the resolution seen by AFP threatens to draw up a sanctions black list of individuals, groups and entities who support the ISIL group and the Al-Nusrah Front in Syria.

The draft "calls on all member states to take national measures to suppress the flow of foreign terrorists" to ISIL and Al-Nusrah and threatens to slap sanctions on those involved in recruitment.

It also warns governments that trade with the terrorists groups, who now control oilfields and other potentially cash-generating infrastructure, "could constitute financial support" that may lead to sanctions.

The council accuses the terrorists of carrying out atrocities, citing the targeting of civilians in Syria and mass executions, extrajudicial killings of Iraqi soldiers and targeted persecutions of religious minorities in Iraq.

It warned that such attacks may constitute a crime against humanity.

The draft resolution states that the Council is acting under chapter VII of the UN charter, which means the measures could be enforced by military force or economic sanctions.

Negotiations on the resolution forged ahead as Iraqi President Fuad Masum tasked Haidar al-Abadi to form a new government able to lead the fight against the terrorist groups.

The council on Thursday adopted a unanimous statement calling on governments to help Iraq cope with a humanitarian crisis sparked by a foreign-hatched offensive.

NJF/NJF