TOLUCA, Mexico — US President Barack Obama urged Ukraine's government Wednesday to refrain from using violence against peaceful protesters, warning of “consequences” if any further abuses take place. Obama made his remarks during a visit to Mexico as the European Union scheduled urgent talks to mull sanctions in the wake of clashes between police and anti-government protesters in Kiev that have left more than 50 people dead. The Obama administration placed 20 top Ukrainian officials on a visa blacklist as it threatened to take punitive sanctions against individuals responsible for the violence. Ukraine's embattled President Viktor Yanukovych announced a truce with the opposition, which Obama said would be a welcome step toward dialogue if implemented. However, the truce was shattered when fierce clashes between thousands of demonstrators and heavily-armed riot police in Ukraine's capital erupted anew Thursday and at least 25 protesters were killed. — Agencies