"Let me stress that the reductions I have announced are not part of a handover of security responsibility at the operational level," Reid told the House of Commons.
"We will stay as long as we are needed, and wanted, and until the job is done," he pledged.
He said the reduction was made on operational rather than political grounds.
Reid said civil war in Iraq was "neither imminent nor inevitable".
"Our analysis is that civil war is neither imminent nor inevitable," Reid said.
Though violence had surged in some areas, he noted the pleas for calm from the leaders of Iraq's rival communities.
A new committee of Iraqi ministers, military staff and senior coalition figures would start an assessment within the next few weeks of whether conditions were ready for some provinces to begin the handover process.Güncelleme Tarihi: 20 Eylül 2018, 18:16