MOSCOW — Diplomatic rancor flared anew on Wednesday between Belarus and the European Union, as the former Soviet republic accused the bloc of pursuing a “dead-end” policy of escalation.

At the center of the dispute is the human rights record of President Aleksandr G. Lukashenko’s government, regarded as the most authoritarian in Europe. Western governments have been gradually increasing pressure on it in the hope that political and economic isolation will force political liberalization. But a move by the European Union on Tuesday to impose new sanctions touched off a cycle of diplomatic retaliation and counter-retaliation that has sharply worsened the already fraught relations between Belarus and the West.

“Brussels and the capitals of the European Union should not forget that tactics of intimidation do not work on Belarus,” the Belarus Foreign Ministry said in a statement on Wednesday. “Under conditions of unilateral pressure, the normalization of relations is not possible.”