IRBIL, Iraq (AP) — Iraq’s top Kurdish leader warned visiting Secretary of State John Kerry on Tuesday that a rapid Sunni insurgent advance has already created “a new reality and a new Iraq,” signaling that the U.S. faces major difficulties in its efforts to promote unity among the country’s divided factions.

The U.N., meanwhile, said more than 1,000 people, most civilians, have been killed in Iraq so far this month, the highest death toll since the U.S. military withdrew from the country in December 2011.