A controller controls a hybrid electric vehicle. The hybrid electric vehicle includes an engine, a motor arranged in a power transmission path between the engine and a drive wheel, and a clutch arranged in the power transmission path between the engine and the motor. The controller idles the engine in accordance with a target engine rotation speed and operates the motor in accordance with a target motor rotation speed when the clutch is in a disengagement state. When the clutch is in the disengagement state and the engine is idling, the target motor rotation speed is less than the target engine rotation speed.