A crackdown by security forces on Tuesday triggered a storm of international condemnation, in Ukraine's worst crisis since the collapse of the Soviet Union.
Ban was following developments in Ukraine "with increasing alarm," his spokesman Martin Nesirky said in a statement.
"He urges an immediate end to the violence in the strongest terms and again stresses that resorting to such measures by any side is totally unacceptable.
"The secretary-general equally urges the government to desist from the use of excessive force, underscoring the need for the authorities to abide by international human rights norms."
"He appeals to the Ukrainian authorities to act decisively in brokering a peaceful end to the crisis in a way that is in keeping with the demands and the aspirations of the Ukrainian people," the statement added.