The two sides constantly blame each other for shelling civilian areas - this one on the outskirts of Donetsk
Ukrainian troops rest on a tank
The aftermath of shelling in the city of Donetsk
Many civilians have fled the Donetsk fighting
Ukraine's crisis has been caused by the West, Russian President Vladimir Putin says, as he considers Franco-German proposals to end fighting between the government and pro-Russia rebels.
Western countries had broken pledges not to expand Nato and forced countries to choose between them and Russia, Mr Putin told an Egyptian newspaper.
The comments come amid new hopes of a peace deal this Wednesday.
Russia denies accusations of sending troops and supplying the rebels.
The fighting in eastern Ukraine has claimed more than 5,300 lives and driven 1.5 million people from their homes.
At least nine Ukrainian soldiers have been killed in the past 24 hours, officials say.
Fighting is said to be intense around the town of Debaltseve, near the rebel-held city of Donetsk.
German Chancellor Angela Merkel and French President Francois Hollande flew to Moscow on Friday to discuss proposals to end the fighting.
The detailed proposals have not been released but the plan is thought to include a demilitarised zone of 50-70km (31-44 miles) around the current front line.
After telephone conversations with Mr Putin and Ukrainian President Petro Poroshenko on Sunday, they announced that a four-way summit could be held in the Belarus capital, Minsk, if the details were agreed before Wednesday.
Mr Putin's spokesman denied media speculation that Mrs Merkel had told the Russian leader that sanctions would be tightened if he did not agree a deal.
"Nobody has ever talked to the president in the tone of an ultimatum - and could not do so even if they wanted to," Dmitry Peskov told Govorit Moskva radio on Monday.
European Union foreign ministers meeting in Brussels agreed more sanctions against Russian and rebel officials on Monday - but put them on hold for a week to give the peace effort a chance.
- 5,358 people killed and 12,235 wounded in eastern Ukraine
- Fatalities include 298 people on board flight MH17 shot down on 17 July
- 224 civilians killed in three-week period leading up to 1 February
- 5.2 million people estimated to be living in conflict areas
- 921,640 internally displaced people within Ukraine, including 136,216 children
- 600,000 fled to neighbouring countries of whom more than 400,000 have gone to Russia
Source: Figures from UN High Commissioner for Human Rights 3 February, and UN report, 21 January
Mrs Merkel is due to brief US President Barack Obama in Washington later on Monday on the peace plan as the US considers sending weapons to the Ukrainian government.
There is pressure in Washington on President Obama to adopt a tougher stance, the BBC's Rajini Vaidyanathan reports from the US capital.
Some officials, as well as senior Republicans such as Senator John McCain, argue that some form of military support is necessary, our correspondent adds.
But Mrs Merkel told a security conference at the weekend that she could not "imagine any situation in which improved equipment for the Ukrainian army leads to President Putin being so impressed that he believes he will lose militarily".
US Secretary of State John Kerry has denied any rift with EU leaders, saying, "I keep hearing people trying to create one. We are united, we are working closely together."
'Artificial choice'
At the start of a visit to Egypt, President Putin renewed his attack on Western countries for their "hollow" promises not to expand Nato to include former Soviet countries, and therefore ignoring Russian interests.
There had been attempts, Mr Putin told Egypt's al-Ahram newspaper, "to tear states which had been parts of the former USSR [Soviet Union] off Russia and to prompt them to make an artificial choice 'between Russia and Europe'.
He went on to accuse them of supporting a "coup d'etat in Kiev" - a reference to the ousting of former Ukrainian President Viktor Yanukovych last year.
He lost power amid protests over his decision to scrap a deal that would have seen Ukraine establish closer ties with the European Union.
Since then, Russia has annexed Ukraine's Crimea Peninsula and rebels in the east have sought to establish full control over the regions of Donetsk and Luhansk.
- A ceasefire signed by Ukraine and pro-Russian separatist rebels on 5 September 2014 in Minsk, Belarus
- They agreed to 12 points including pulling back heavy guns by at least 15km (9 miles), releasing prisoners, allowing access to international observers, and setting up a buffer zone on the Russia-Ukraine border. Foreign mercenaries were to withdraw and Donetsk and Luhansk would get wider self-rule
- But military clashes never entirely stopped. Each side accused the other of violating the deal and violence later flared the length of the ceasefire line
- Rebels also held their own local elections in November 2014, in defiance of Kiev. The government responded by saying it would scrap partial autonomy for Donetsk and Luhansk