Russian President Vladimir Putin, French President Emmanuel Macron, German Chancellor Angela Merkel and Ukrainian President Volodymyr Zelensky (L to R) attend "Normandy four summit" in Paris, France, Dec. 9, 2019. Ukraine and Russia agreed on a full and comprehensive implementation of the ceasefire in eastern Ukraine before the end of 2019, leaders of Russia, Ukraine, France and Germany announced in Paris on Monday evening following their talks called "Normandy four summit". (Xinhua/Gao Jing)