Ukrainian President Petro Poroshenko has said his country is "prepared for total war," as fighting between Ukrainian forces and pro-Russian separatists continues around the rebel-held city of Donetsk.
In an interview with the German daily "Bild", Poroshenko said, "I am not afraid of war with Russian troops."
"We are prepared for a scenario of total war... We don't want war, we want peace and we are fighting for European values. But Russia does not respect any agreement," he said in the interview published on November 17.
The conflict, which has killed more than 4,000 people since April, persists despite a September 5 cease-fire.
Poroshenko said Ukraine's armed forces were better prepared now, and Ukraine had the support of the "entire world."
Earlier on November 16 during a visit to Bratislava, Poroshenko said the conflict in the east would "end within two weeks" if the cease-fire signed in Minsk in September was implemented.
In the rebel stronghold of Donetsk, fresh shelling broke out in the afternoon on November 16 after a quiet morning, an AFP reporter said.
Ukraine's Interior Ministry said three volunteers fighting with Ukrainian forces had been killed in neighboring Luhansk, where rebels also control much territory.
Meanwhile, Dutch authorities said recovery workers in rebel-controlled eastern Ukraine began to collect debris from the crash site of Malaysia Airlines Flight 17 on November 16, four months after the plane was brought down.
The operation is being carried out under the supervision of Dutch investigators and officials from the Organization for Security and Cooperation in Europe.
The operation is expected to take around 10 days.
Debris will first be collected at a location near the crash site before being taken to the Ukrainian city of Kharkiv and then to the Netherlands.
All 298 people on board the flight from Amsterdam to Kuala Lumpur were killed. Most of the victims were Dutch.
Kyiv and the West accuse pro-Moscow separatist rebels of having shot down the plane on July 17 with a missile supplied by Russia.
Both Moscow and the rebels deny this, instead blaming Ukrainian government forces for downing the aircraft.