Over 5,000 USA troops have been deployed in Iraq to support the Iraqi forces during the battles against IS militants.
Al-Hadithi explained that the agreement was reached "after the victory achieved by the Iraqi forces against the forces of terrorism", adding that the nature of the next phase requires a presence of another kind.
Now the US-led coalition and the Iraqi government have agreed to withdraw troops from the country.
Hadithi stressed that the drawdown was still in its early stages and at present did not mark the beginning of a complete withdrawal of US forces.
Iraq's military declared in December that it had "fully liberated" Iraq from ISIS and retaken full control of the Iraqi-Syrian border.
As of late September previous year there were 8,892 US troops in Iraq.
The US first launched airstrikes against IS in Iraq in August 2014, as part of a military intervention which was initially described as "limited". Iraq's oil ministry has ordered the state-held North Oil Company to draft "an urgent plan" for rehabilitating the oil fields in Nineveh. The prime minister has previously stated that 's military will need American training for years to come.
The spokesman said that coordination with the United States will be continuing, and USA officials have long suggested their presence in Iraq is "permanent", suggesting any drawdown would be limited.
"Great power competition, not terrorism, is now the primary focus of US national security", Defense Secretary Jim Mattis said last month in remarks outlining the strategy. Still, U.S. officials have warned that ISIS remains a threat capable of carrying out attacks on the West and that it could regain its territory if Iraq and Syria aren't stabilized. Gen. James Glynn told reporters during a Pentagon briefing last month.
"Enabled by accelerated successes following the liberation of Mosul, the Coalition will shift its focus in Iraq from enabling combat operations to sustaining military gains against Daesh". US troop numbers eventually reduced to 40,000 before the complete withdrawal in 2011.