The soldiers are being sent to help combat Islamic State (I.S.) militants who have been persecuting tens of thousands of Christians.
The extremist group has advanced across large parts of Iraq and Syria.
Troop numbers in Iraq will be doubled by this new deployment.
Mr Obama is also asking Congress for more than £3.1 billion to help fund the fight but he stressed the soldiers would not be involved in combat.
I.S. has forced thousands of Christians to flee their homes and in some parts of the Middle East the entire Christian population has left.
Earlier this year militants issued a convert to Islam or die ultimatum to believers.
White House spokesman Josh Earnest said: "US troops will not be in combat, but they will be better positioned to support Iraqi security forces as they take the fight".