Vice President Joe Biden Wednesday launched a new American military mission in Iraq, ushering in a fresh phase in a seven-year-old deployment that has cost the lives of more than 4,400 troops. Addressing soldiers at Camp Victory outside Baghdad a day after the US combat role in Iraq officially came to an end, Biden expressed confidence that the worst days of the conflict were over. Calling for unity around the new mission, he also acknowledged that the 2003 invasion had split US public opinion. “It is no secret that this war has divided Americans but they have never shrunk from the united support of the United States military,” Joe Biden said. “Now is the time to put these differences behind us,” he added. “Operation Iraqi Freedom is over but American engagement with Iraq will continue with the mission that began today, Operation New Dawn.” The US vice president acknowledged the heavy toll paid by Iraqis during the conflict but expressed confidence that the worst was over. “Today is also an important acknowledgement of the Iraqi losses in this conflict,” Biden said. “Tens of thousands of security forces and innocent civilians have been killed. Many times that number have been wounded and displaced. “The Iraqi people have rejected their ugly face of violence... I truly believe that the darkest days are now behind us. A total of 49,700 troops are currently deployed in Iraq for the new training and counter-terrorism mission that will continue until a full withdrawal at the end of next year. Defense Secretary Robert Gates, who was also in Iraq to mark the launch of the new mission, told the troops remaining in the country that their work was still vital despite the shift in spotlight to the war in Afghanistan.