BAGHDAD, Iraq (CNN) -- The initial group of U.S. military advisers was to arrive in Iraq soon, a senior defense official said, as crowds paraded nationwide in a show of unity for the government.
This first detail is expected to be very small, the official said. The total number of U.S. military advisers who will eventually deploy will be about 300.
In addition, some U.S. military personnel already at the U.S. Embassy in Baghdad will be reassigned and become advisers, Pentagon spokesman Rear Adm. John Kirby said.
The first group of advisers will conduct an initial assessment of Iraqi troop capabilities and of what may be needed for a larger group of U.S. advisers, including additional security measures where they may be deployed, a senior defense official said Friday.
Meanwhile, Shia cleric Muqtada al-Sadr called on his supporters to hold a military parade nationwide to enhance unity among Iraqis. He has previously called for people to protect the country's Shiite and Christian religious sites.
More than 1 million Iraqis have fled their homes this year because of conflict, the U.N. refugee agency said Friday. The number is likely to rise as Islamist militants and Iraqi security forces battle for control.
An estimated 800,000 people left Iraq's second-largest city of Mosul after it fell to fighters from the Islamic State in Syria and Iraq (ISIS), the International Committee of the Red Cross said. The city has a population of 1.6 million.
ISIS, born from an al Qaeda splinter group and supported by Sunni factions, continues its fierce advance in Iraq.
Violence erupted Saturday in Baghdad, where authorities are digging in to confront the group if it approaches the capital.
Two roadside bombs killed four people and wounded seven others in the city's southeast, police said. A roadside bomb exploded in the sprawling Shiite neighborhood of Sadr City, killing one person and wounded six others.
But there were no immediate claims of responsibility.
Prime Minister Nuri al-Maliki's Shiite-dominated government is accused of fostering sectarian tensions by marginalizing Iraq's Sunni Arab and Kurd minorities.
Obama told CNN on Friday that U.S. military efforts are hopeless without a change in government.
"If we don't see Sunni, Shia and Kurd representation in the military command structure, if we don't see Sunni, Shia and Kurd political support for what we're doing, we won't do it," he said.
The complete interview will be aired Monday on CNN's "New Day."
The United States withdrew its final troops from Iraq in 2011, nearly nine years after leading the invasion that ousted longtime leader Saddam Hussein.
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