Baghdad, Oct 24: US Secretary of State Rex Tillerson arrived in Baghdad on Monday on an unannounced visit to meet with Iraqi leaders, an Iraqi Foreign Ministry official said. Tillerson is expected to hold talks with top Iraqi officials to discuss bilateral relations and the tensions between Baghdad and the semi-autonomous region of Kurdistan following the last month's referendum on independence, Xinhua cited an official as saying on condition of anonymity. Tillerson would also discuss the efforts to rebuild cities and towns after the defeat of Islamic State (IS) group from the major IS strongholds in the country, he said. Hundreds of US troops are already in Iraq, serving as trainers and advisers, in an attempt to help the country win the battle against IS terrorists in the country. The US-led international coalition has also been conducting air raids against IS targets in both Iraq and Syria. Tillerson's visit came as tensions are escalating between Baghdad and the region of Kurdistan after the Kurds held a controversial referendum on the independence of the Kurdistan region and the disputed areas.