Brown was also expected to meet Jalal Talabani, the Iraqi president, Bayan Jabr, finance minister, and Lieutenant-General Graeme Lamb, Britain's senior military officer in the region, a spokesman said.
In the UK, the opposition Conservative party has called on the British parliament to back a formal inquiry into Blair's decision to go to war in Iraq.
Liam Fox, the Conservative party's defence spokesman in parliament, said: "We want the principle established that there must be an inquiry. It's about making sure we don't make the same mistakes again."
Blair has ruled out an inquiry while British troops are deployed in Iraq.
The government was expected to defeat the motion, but interest would focus on how many members of Blair's Labour party will back the proposal.
At the time the Conservative party supported Blair's decision to back the US-led invasion.