By Gabriela Baczynska and Bart H. Meijer BRUSSELS (Reuters) -European Union leaders will impose new sanctions on Russia, freezing its assets, halting its banks’ access to European financial markets and hitting “Kremlin interests” over its invasion of Ukraine, senior officials said on Thursday. The bloc will also target Russia’s trade, energy and transport, among other sectors, and include export controls in what the EU’s foreign policy chief, Josep Borrell described as “the harshest package of sanctions we have ever implemented.” An emergency summit starting at 1900 GMT will also discuss offer…