Fierce fighting against Islamic State militants in Iraq sets the backdrop for a government scrambling for unity.

Some Sunni tribal fighters have sided with Islamic State, fueled by hatred after they felt marginalized by former Prime Minister Nuri al-Maliki.

But perhaps Vice President Iyad Allawi's endorsement of Prime minister Haider al-Abadi will help ease Sunni-Shi'ite tensions.

He says he stands by the new Prime Minister's vision to bring more Sunnis into the government.

(SOUNDBITE) (English) IRAQI VICE PRESIDENT, IYAD ALLAWI, SAYING:

"I told (Abadi) we will be with him all the way if he moves along the right road to recovery.''

Allawi, a secular Shi'ite Muslim, has accused former premier Nuri al-Maliki of acting like Saddam Hussein.

Although now Prime Minister Abadi comes from the same political party as Maliki, he's regarded as more inclusive.

(SOUNDBITE) (English) IRAQI VICE PRESIDENT, IYAD ALLAWI, SAYING:

"What we need to do