Hollywood star Angelina Jolie has urged world leaders to do more to bring the conflict in Syria and Iraq to an end.

The actress was visiting a Kurdish refugee camp in Dohuk, northern Iraq, in her role as special envoy of the U.N. High Commissioner for Refugees, when she made the comments.

The 39-year-old star met Yazidi refugees who have been forced to abandon their homes in Mosul, after their villages were seized by the Islamic State.

More than a million refugees are now living in the camp as the Syrian civil war rages on and ISIS continue to occupy large swathes of Iraq.

Jolie took a tour of the camp where she met with families living in makeshift homes. Addressing the hundreds of refugees she said: "Since I was last here in Iraq, another two million people have been forced from their homes. The brutality of the conflict and the speed and scale of the displacement has shocked the world and help has come, but not nearly enough. It is past time for leaders on all sides to find a common ground and a way to move forward.

"It is not enough to defend our values at home, we have to defend them here in the camps and in the informal settlements across the Middle East and in the ruined towns of Iraq and Syria," she added.

The Unbroken director appealed to the international community to end the suffering, so that the displaced families can return to their homes in Iraq and Syria.

Angelina said: "We are being tested here as an international community and so far, for all of the immense efforts and good intentions, the international community is failing. The people I met today need to know that we will be with them, giving them the support they need to survive for every day that they are displaced," she explained.

"And above all, they need to know that one day they will be able to go home and that there will be an end to this suffering."

The Hollywood star has visited the Middle East on several occasions in her UN role including a tour of a refugee camp in Erbil in the Kurdistan region of Iraq in 2012.

She has also visited war-torn parts of Africa as part of her campaign to bring an end to the use of rape as a weapon of war.

Earlier, Jolie condemned the Nigerian Islamist militant group Boko Haram for its insurgency in northeastern Nigeria and called on the international community to bring them to justice.