John Ging, the director of UN humanitarian operations, told the Security Council late Tuesday (early Wednesday European time) that the humanitarian situation in eastern Ukraine was deteriorating as access to power and water became more difficult, homes were destroyed and health workers fled.
The violence in the region, particularly in urban areas, will put more people at risk and lead to "an increase in the numbers killed" if no diplomatic solution can be reached, Ging said.
"Immediate action is therefore required to prevent this," he added.
Nearly 1,400 people have been killed and more than 4,000 injured in the unrest, Ging told council members at the emergency meeting, which was requested by Russia.
Earlier on Tuesday, the UN's refugee agency said 700,000 people have left the country for Russia during the four-month conflict, and an additional 117,000 people have been displaced inside Ukraine. Around 1,000 people flee the combat zone ever day, according to UN figures.
In the rebel-controlled city of Donetsk, at least two civilians were killed in heavy clashes on the outskirts of the city. Local administration said the fighting was focused on the western Petrovsky suburb as government forces carried on with their offensive to oust the pro-Russian separatists.
Nearly four million people in eastern Ukraine are affected by the violence, Ging said. In Donetsk and Luhansk power has been cut to a few hours a day, while health supplies are running low and an estimated 70 percent of healthcare personnel have fled, he added.
Russia's UN Ambassador Vitaly Churkin called the situation in the region "disastrous." He accused Ukraine's government of indiscriminately shelling houses, saying 80 percent of houses have been destroyed in many small towns.
Ukraine, US blame Russia
Ukraine's deputy UN ambassador Oleksandr Pavlichenko has denied there is a humanitarian crisis in Ukraine, but said the conditions in Donetsk and the nearby city of Luhansk were serious.
"The situation is manageable by the government of Ukraine, which remains open to cooperation with international partners," he said.
In Washington, the Pentagon said Russia had moved 10,000 troops closer to Ukraine's eastern border. The US and Kyiv accuse Moscow of providing support to the separatists in the east.
The deputy US ambassador, Rosemary DiCarlo, claimed Russia could singlehandedly stop the unrest in the region.
"The surest way to end the violence is for Russia to stop the flow of fighters, weapons and money from Russia into eastern Ukraine," she said.
dr/lw (AP, dpa, AFP)