Speaking after meeting with Iraqi Prime Minister Nuri al-Maliki in Baghdad today, Brown also said he believed the southern Al-Basrah Governorate could be handed over to full Iraqi control in the next two months.
"By the end of the year, the British forces, which have been 5,500, can be reduced to 4,500, and by the end of the year, indeed by Christmas, 1,000 of our troops can be brought back to the United Kingdom and to other purposes," Brown said on his first trip to Iraq as prime minister.
"What we propose to do over these next few months is to move from a situation where we have had a combat role to one where we have an overwatch role, where the Iraqis increasingly take over with the 30,000 [security forces] that they have, responsibility for their own security and with us, as the British, having an overwatch so that we maintain a facility for reintervention, if necessary, but at the same time, we play a greater role in training future security forces in Iraq."
Al-Maliki confirmed that Iraq was prepared to take over security of the southern province within two months.
British troops have been stationed in southern Iraq since the U.S.-led invasion in 2003.
The troops vacated their last remaining base in Al-Basrah city last month, withdrawing to an air base on the outskirts of the city.
Brown is also expected to meet with British forces and military leaders in Al-Basrah Governorate.
Brown's trip comes before he makes a key statement on Iraq to parliament next week.
(compiled from agency reports, BBC)