The United Nations has declared the highest emergency level for the conflict in Iraq, which continues to escalate as government troops and Sunni militants battle for control of the region.

Clashes between government troops and the Islamic State of Iraq and Syria (ISIS) erupted early Thursday in Fallujah, which is west of Baghdad.

The clashes killed four children, in addition to a woman and at least 10 fighters, according to Al Jazeera English.

Fallujah was taken over by ISIS in early January, when the militants seized most of the Western Anbar province, along with the capital of Ramadi.

The U.N. therefore declared the situation a "Level 3 Emergency," which will prompt additional goods such as assets and funds to bring aid to the displaced. U.N. special representative Nickolay Mladenov said that the "scale and complexity of the current humanitarian catastrophe" prompted the declaration of the emergency level.

The U.N. Security Council also said that it will support the new premier-designate Haider al-Abadi in the hopes that he can successfully form an "inclusive government" that can stop ISIS rebels. ISIS has brought Iraq into its worst crisis since U.S. troops withdrew from the region in 2011.

The violent takeover has forced tens of thousands of Yazidis, a pre-Islamic religious minority, to flee to the Sinjar Mountains to escape persecution.

Both the U.S. and the Iraqi military have dropped food and water for the Yazidis, and Kurds from Syria battled ISIS fighters to open a corridor in the mountain, which allowed around 45,000 people to escape.

President Barack Obama said Thursday that the U.S. has stopped the siege on Sinjar, but that U.S. airstrikes will continue. The U.S. has been executing airstrikes this week against ISIS fighters in an effort to stop their advancement on other Kurdish towns.

Obama, speaking from Martha's Vineyard in Massachusetts, said the U.S. helped thousands of Iraqis flee from the mountain, and it is not likely that more airdrops of food, water and other necessities are needed.

The U.N. announced that it would provide aid to those who escaped the mountain, as well as to 400,000 other Iraqis who fled since June to Dahuk, a Kurdish region. Other minorities have fled to other parts of the Kurdish region.

Fifteen million Iraqis have been displaced due to the fighting, which began when rebels seized Mosul, the second-largest city in the country. Since then, ISIS has been capturing cities across the country.

Iraq's government in Baghdad is also in a state of disarray, as the president nominated Shiite politician Haider al-Abadi to form the next government, but current Prime Minister Nouri al-Maliki refuses to step down.

On Wednesday, al-Maliki said he would not give up power until a federal court rules on what he considers the "constitutional violation".

Al-Maliki said he should have a third term, but he is becoming politically isolated by both Western and Middle Eastern powers, who support al-Abadi.

Al-Abadi has been given 30 days to propose a new cabinet. The U.N. Security Council told al-Abadi to quickly form "an inclusive government that represents all segments of the Iraqi population and that contributes to finding a viable and sustainable solution to the country's current challenges."