A senior United Nations official expressed regret over Russia deploying forces in eastern Ukraine on a "peacekeeping mission" and warned that there is a risk of a "large-scale conflict" breaking out and that efforts must be made to avoid it.

Rosemary DiCarlo, the UN Under-Secretary-General for Political Affairs, said at an emergency Security Council meeting on Monday regarding Ukraine that the UN supports the independence, unity, and territorial integrity of Ukraine within its internationally recognized borders.

Russian President Vladimir Putin had ordered the deployment of forces in two separatist regions in eastern Ukraine after recognizing their independence on Monday, exacerbating a crisis that the West fears could escalate into a major war.