The UN's assistant secretary-general for human rights warns there may be a major exodus of people from the troubled eastern region of Ukraine.
A top UN rights official has warned of a risk of a major exodus from rebel-held areas of east Ukraine because of the near collapse of basic services there.
Ivan Simonovic also cautioned in an interview with AFP on Monday against expecting that Sunday's election would provide a "miracle" that would resolve a crisis that threatens Ukraine's very existence, saying the window of opportunity was closing fast.
The visiting UN assistant secretary-general for human rights said the international community should heed the lessons of the war in the former Yugoslavia to ensure that such a heavy price is not paid in Ukraine.
He said the rebel-held region of Donetsk in the country's eastern coal and steel heartland was running short of crucial supplies such as medicines including insulin.
"I have an impression that Donetsk is on the verge of collapse of social services ... the overall system is, I think, on the verge of collapse."
He said that during his discussions with local people in the Donetsk region it was "frightening" how many people were contemplating leaving.
"And if things do not improve, we could have a major wave of displaced persons coming from that area."
Simonovic, a diplomat from Croatia, said he did not believe the situation in Ukraine had yet reached the "point of no return" but warned that could happen if there was an escalation of violence.
"That window of opportunity (to end the crisis) may be closing and the opportunity, while is still open, should be used both nationally and internationally."
"Elections will be the beginning of a new phase," he said, just days before the presidential poll being held in the face of Russia's annexation of crimea last month and the uprising in the east.
"But to expect a miracle out of elections is, I think, unrealistic," he added.
"We are facing a country that is increasingly being divided. We are facing a country that may be heading to a very dramatic future scenario. However, we are dealing with a country that can be saved."