Washington has sought to separate the need for urgent support to combat militants from support for al-Maliki . ANALYSIS : Iraqi Prime Minister has vowed to fight the nomination of his successor . The U.S. and Iraq have been at odds over who should succeed Saddam Hussein since shortly after he was toppled in 2003. The United States backs the prime minister-designate and has stepped up aid . The militant group Islamic State has made sweeping gains in Iraq 's north .
ANALYSIS : Iraqi Prime Minister has vowed to fight the nomination of his successor . The U.S. and Iraq have been at odds over who should succeed Saddam Hussein since shortly after he was toppled in 2003. The United States backs the prime minister-designate and has stepped up aid . The militant group Islamic State has made sweeping gains in Iraq 's north .