US Secretary of State Rex Tillerson said today that Ukraine was the sole sticking point keeping the United States and Russia from forging a closer relationship. <br/><br/>Tillerson's focus on Ukraine came as he met with European diplomats at the Organisation for Security and Cooperation in Europe, established during the Cold War to serve as a bridge between East and West. <br/><br/>Tillerson insisted the US could never overlook Russia's "attempted annexation" of Crimea or Moscow's military intrusion in eastern Ukraine.<br/>