WASHINGTON D.C., June 24, 2016 (Xinhua) -- The International Monetary Fund(IMF) Managing Director Christine Lagarde speaks at the IMF headquarters in Washington D.C. the United States, on June 24, 2016. The International Monetary Fund (IMF) has called on Britain and the EU authorities to work collaboratively to ensure a smooth transition, after Britain voted to leave the European Union in a referendum on Thursday. (Xinhua/Yin Bogu)