Christian and Muslim aid groups have united to issue an urgent call for action by international organizations to work for an end to the dire and "horrific" suffering in Iraq.

European Union leaders pledged Saturday to increase endeavors to combat the Islamic State extremist Sunni group and take on the threat created by fighters going back to the EU from Iraq and Syria.

More than 1.5 million people are in need of urgent humanitarian assistance in Iraq and the number is set to increase said the international humanitarian and development network ACT Alliance.

"This is starting to become a runaway crisis, and the world must rise up quickly to save the lives of the people who have fallen victims to dangerously armed militant groups," said John Nduna, ACT general secretary.

The U.S. air and advisory campaign against the militants in Iraq is costing American taxpayers more than $7.5 million a day, the Pentagon said Friday, Time magazine reported.

ACT said the since the Islamic State jihadist group continues encroaching into the region with violent take-over of large swaths of land in northern and western Iraq.

The result is Iraq is now contending with one of the largest internal displacements in the world.

The statement is endorsed by the ACT Alliance, Muslim Charities Forum, CAFOD, Islamic Help, Muslim Charity Helping the Needy, Muslim Aid, Human Relief Foundation, Lutheran World Federation, World Student Christian Federation and World Vision International.

"We call for international pressure at all levels of the United Nations and the League of Arab States, and from people, governments and institutions of goodwill, to urgently and adequately address the situation in Iraq," said the statement.

"There is an urgent need for immediate protection of civilians from further attacks, and up-scaled humanitarian assistance for the hundreds of thousands who are now refugees or internally displaced," said Nduna.

ACT Alliance members and partners are delivering assistance in the Kurdish and Karbala regions, including Nineveh plain area in the northeast of Mosul.

The assistance comprises food and non-food items, psychosocial support, water, sanitation and hygiene.