Energy issues in eastern Ukraine are taking a humanitarian toll as residents grow concerned about supplies for the coming winter, a U.N. report said Wednesday.

The U.N. High Commissioner for Human Rights published a report on the situation in eastern Ukraine.

"For almost half a year, residents of the areas affected by the armed conflict have been deprived of their fundamental rights to education, to adequate healthcare, to housing and to opportunities to earn a living," U.N. High Commissioner for Human Rights Zeid Ra'ad al-Hussein said in a statement. "Further prolongation of this crisis will make the situation untenable for the millions of people whose daily lives have been seriously disrupted."

The report said residents across Ukraine are growing concerned about energy issues, as they fear there could be a natural gas shortage this winter. This is a particular concern for those Ukrainians internally displaced by the conflict.

Political upheaval in Ukraine in November left an already-struggling economy in shambles. Russian energy company Gazprom cut gas supplies to Ukraine earlier this year because of mounting debt.

Russia, Ukrainian and European leaders are negotiating a deal that would ensure adequate winter gas supplies.

The U.N. report said more than 3,500 people have died as a result of the fighting in eastern Ukraine since mid-April.