Expressing alarm over escalating tension in the region, the UN chief asked world leaders to work towards a durable and fair political solution.
Ban urged the international community to help the key actors calm the situation, as tension and mistrust grows in Ukraine.
"I am increasingly alarmed by the developments in Ukraine," Ban said in a statement yesterday.
"Recent events in Crimea in particular have only served to deepen the crisis," he said.
"Since the beginning of this crisis, I have appealed to all parties to de-escalate tensions and to engage in direct and constructive dialogue in order to forge a peaceful way forward."
He said that a further deterioration of the situation "would have serious repercussions for the people of Ukraine, the region and the global community."
The UN chief also asked relevant authorities to ensure that everyone's rights are respected in Ukraine.
"At this crucial juncture, we cannot afford either miscalculations or inaction," he cautioned.
Last week, Crimean lawmakers voted to break away from Ukraine and join Russia. They would hold a referendum on March 16 to validate the decision.
Russia yesterday said it is drafting a series of counterproposals to a US plan for a negotiated solution to the Ukranian crisis. The move came as Russian forces strengthened their control over Crimea, home to Moscow's Black Sea Fleet.
The Security Council, meanwhile, met in closed consultations yesterday on Ukraine. The meeting, the panel's fifth on the issue in 10 days, had been requested by Ukraine.
UN Assistant Secretary-General for Human Rights Ivan Simonovic, who is in Ukraine until March 15 to assess human rights situation, would develop recommendations for further action by the world body.
He has held meetings with the acting Foreign Minister, the diplomatic community in Kiev, international organisations and civil society representatives.