Violence continued unabated across Iraq as US Secretary of Defense Robert Gates toured the country on Tuesday and met with Prime Minister Nuri Al-Maliki. Gates' unscheduled stop in the country came after visits to Israel and Jordan, according to a report of the German News Agency "DPA". In Iraq, Gates met with Iraqi and US military officers in the joint Iraqi-US military base of Talil, near the southern Iraqi city of al-Nasiriyah. Gates hailed the soldiers' cooperation in securing the city as a model of US forces' new role in the country. Gates' arrival was the second visit by a top US official to Iraq since US troops withdrew from urban areas. Vice President Joe Biden celebrated US Independence Day with his country's troops on July 4 in Iraq. Gates, whose last visit to Iraq was in September 2008, was expected to visit Iraq's Kurdish region on Monday evening, and to meet with Masoud Barzani, incumbent president of the Kurdistan semi-autonomous region.