KYIV, Ukraine (AP) — Ukraine’s president is visiting the area of conflict in his country’s east amid an escalation of tensions that has raised fears of a resumption of large-scale hostilities. The conflict with Russia-backed separatists in eastern Ukraine erupted shortly after Moscow’s 2014 annexation of Ukraine’s Crimea peninsula. Officials in Ukraine and the West have raised concerns about increasingly frequent cease-fire violations in the country’s industrial heartland. They also have expressed worries about Russian troops’ buildup along the border. Ukrainian President Volodymyr Zelenskiy headed to the conflict area Thursday, tweeting “I want to be with our soldiers.” A senior Kremlin official sternly warned Ukraine against using force to reclaim control of the rebel east.