ROUGH CUT (NO REPORTER NARRATION)<br/> <br />U.S. Secretary of State John Kerry says tension between Russia and U.S. over Ukraine 'has the capacity' to affect relationship with Moscow on Syria.<br/> <br />The United States and the European Union will respond on Monday (March 17) with a "serious series of steps" against Russia if a referendum in Ukraine's Crimea region goes ahead on Sunday, U.S. Secretary of State John Kerry said on Thursday (March 13).<br/> <br />Kerry told a congressional hearing he hoped to avoid such steps, which include sanctions, through discussions with his Russian counterpart, Sergei Lavrov, in London on Friday (March 14).<br/> <br />"If there is no sign of any capacity to be able to move forward and resolve this issue, there will be a very serious series of steps in Europe and here with respect to the options that are available to us," Kerry said in testimony on the State Department's 2015 budget request.<br/> <br />Kerry went on to add, "Now our choice is not to be put in the position
