Ukrainian President Petro Poroshenko is pleading with Russia to remove its troops from war-torn eastern Ukraine.
President Poroshenko made his comments Thursday at the outset of a three-day visit to Australia, a key Western ally. Speaking to reporters, he said if Russia closes its border with Ukraine, there will be "peace and stability" within weeks.
Ukraine has repeatedly accused Russia of providing arms and soldiers to rebels who are fighting the Kyiv government. Russia has firmly denied the accusation. It says any Russian soldiers in the area are there on their own accord.
Ukraine on Wednesday ruled out holding peace talks this week, saying the rebels are not interested in a negotiated settlement. The talks were expected to take place Friday in Belarus, but Kyiv said this was impossible after the separatists violated a cease-fire.
The Ukrainian military reported Wednesday that separatists launched 12 attacks just 24 hours after both sides began observing a halt in hostilities dubbed the "Day of Silence." It said the rebels used grenade launchers, anti-tank guided missiles, mortars, small arms and a tank weapon.
The "Day of Silence" was designed to encourage both sides to observe the wider cease-fire agreed to in September, which has been marred by sporadic fighting, and then begin pulling back their heavy weaponry from the front line to form a buffer zone.