According to the final results of the 15 December election, Shia religious parties won 128 out of the 275 seats in the new parliament, but they will need partners to form a government.
Even with the 53 seats from the Kurdish Alliance, the Shia and Kurds are three seats short of a two-thirds majority needed to elect a president and to push through constitutional reforms.
Nizar al-Samaraei, an Iraqi analyst, speaking to Aljazeera in Baghdad on Saturday said: "Iraq now needs a national unity government that includes all sections of the society. A single group or even an alliance of two groups can never express all the expectations and ambitions of the Iraqi people.
"At least four groups should form an alliance in order to meet Iraq's needs of safety and services."
Kurds expected to play'
US State Department spokesman Sean McCormack said the US wanted Kurds, Shias, Sunnis and others to "work together in cross-sectarian, cross-ethnic efforts to think about forming a government."
The spokesman insisted that the decisions would be taken by the parties in Baghdad, and not Washington.
But "the eyes of Iraq will be upon them. The Iraqi people will be looking to them to form an effective, responsible government that responds to their needs and a government that is responsive to all Iraqis, regardless of ethnic group or religious group."
Lionel Beehner, at the Council on Foreign Relations in Washington, predicted that the Kurds would play "the kingmaker's role" in forming a new Iraqi government.
"Some experts suggest that Kurds, most of them secular, may partner up with secular Shia and Sunni parties to prevent Iraq from becoming too Islamist," he told AFP. "But most experts expect the Kurds to align themselves again with the United Iraqi Alliance, Iraq's ruling Shia bloc."
The US State Department refused to comment on the debate between the parties.
"What particular groupings come together to form a government is entirely up to the Iraqis and to the political parties and to the elected representatives of the Iraqi people"
US State Department spokesman
"What particular groupings come together to form a government is entirely up to the Iraqis and to the political parties and to the elected representatives of the Iraqi people," said McCormack.
But the spokesman played down deep divisions between Iraq's religious and ethnic communities.
"Over time, you see in democracies that those sorts of things gradually start to fade and more and more you see groups come together around interests and issues," McCormack said. "That's really a vestige of Saddam Hussein's era where he ruled by dividing and conquering."
McCormack said the Iraqis were at an early stage in the development of a "democratic political class" but added that tremendous progress had been made in the past year and a half.