Ukraine warns a 'great war' is looming with Russia

Ukraine's leadership is calling the conflict in the country's east a great war in which tens of thousands of people could die.

Pro-Russian fighters southeast of Donetsk, preparing a fresh offensive on a key coastal location in eastern Ukraine.

(Transcripts from SBS World News Radio)

Ukraine is calling it a great war in which tens of thousands of people could die.

Ukraine's defence minister says the country is now fighting a war on its doorstep with Russia, the likes of which Europe has not seen since World War Two.

Pro-Russian rebels are still advancing in eastern Ukraine, forcing government forces to withdraw after heavy clashes.

The rebels have gained ground in both the Luhansk and Donetsk regions, and further south around the port of Mariupol.

Greg Dyett reports.

(Click on the audio tab above to hear the full report)

Ukrainian politicians are describing the conflict as a great war and have even referenced this speech from Winston Churchill from June 1940.

"We shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills, we shall never surrender."

And the mayor of Mariupol Yuriy Hotlubey says his town won't be surrendering either.

He says reinforcement works are underway, in and around the city, which he says is now a fortress.

"I would like to quote the British Prime Minister Churchill statement made in 1940: 'We shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender.' These words are very relevant. Of course we would like to avoid that, but our city is getting prepared anyway."

As the fighting continues, Ukrainian and Russian officials are holdings talks with separatist rebels and international monitors, in the Belarus city of Minsk.

Russian President Vladamir Putin says the Ukrainian government is refusing to enter into negotiations over the future of eastern Ukraine.

(Trans) "What is the essence of the tragedy that is happening now in Ukraine? I think the main reason is that the Kiev authorities do not want to conduct substantive political dialogue with the east of the country. And now is the beginning of a very important process in my view - the processs of direct negotiations. We have been working on it for a long time and agreed with President Poroshenko in Minsk such contact are starting now."

NATO Secretary General Anders Fogh Rasmussen has outlined a force which will be able to deploy at short notice, in response to what he calls Russia's "aggressive behaviour."

He says Russia doesn't consider NATO a partner, but rather an adversary.

"I strongly regret that, because I do believe that the right thing for Euro-Atlantic security, would be to develop a strong partnership with Russia but of course, we cannot afford to be naïve, we don't have any illusions we are faced with the reality that Russia considers us an adversary and we will adapt to that situation."

Russia continues to deny accusations that it's providing troops and equipment to the rebels.

More than 2,500 people have died in eastern Ukraine since fighting began in April.

The conflict erupting after Russia annexed Ukraine's Crimea peninsula in March.