Ukraine warned on Thursday that its offensive against pro-Russian insurgents may last another month and rejected calls for a ceasefire as it moved tanks to within striking distance of the rebels' two remaining strongholds.
An AFP team over 20 kilometres (12 miles) south of the eastern hub of Donetsk -- to which most of the militias have retreated -- saw heavy armoured vehicles fan out across the rolling corn and sunflower fields of the economically-vital rustbelt.
A vast column of tanks and military vehicles arrived in the area on Wednesday in an apparent push to surround Donetsk and the neighbouring city of Lugansk, also controlled by the separatists.
An earthmover's engine stuttered in the stifling heat as it dug trenches to help troops dodge artillery strikes from thousands of insurgents who are refusing to give up their bloody three-month drive to join Russian rule.
"We arrived here last night," said a balaclava-wearing soldier named Yuriy as his comrades stretched electric cables to a nearby farm to power up their equipment. He remained tight-lipped about his unit's immediate plans but vowed to fulfil "all orders".
The Ukrainian military said three servicemen had been killed and 27 wounded in the previous 24 hours. Two died when their armoured vehicle hit one of the numerous land mines the separatists have planted to ward off Kiev's relentless advance.
"We can now make a forecast about how long it will take to pull troops back from Donetsk and Lugansk," Ukrainian interior minister advisor Stanislav Rechinsky said in reference to the capitals of the two separatist regions.
"Presumably, this can be done within a month," he told Ukrainian state television.
Rechinsky also said "there will be no air or artillery strikes" against either city because of the inevitable toll in a low-scale war that has already claimed more than 500 lives.
- No talks with 'terrorists' -
Fears of an all-out assault on the two densely populated centres have redoubled European efforts to force Kiev to negotiate truce terms that could help calm the most explosive East-West standoff in Europe since the Cold War.
The tide in a conflict that has threatened the strategic state's very survival turned on Saturday when the insurgents abandoned their symbolic bastion Slavyansk -- a city of 120,000 that now stands emptied of half its population and in dire need of fresh water and medical supplies.
Kiev paints the insurgency as a proxy war being waged by Russian President Vladimir Putin in reprisal for the February ouster of an allied administration and the collapse of his dream to fold Ukraine into a powerful new post-Soviet bloc.
But Kiev's recent string of military successes have also alarmed European leaders who are hoping to secure a truce that can take pressure off the bloc to adopt economic sanctions that could damage their own tight energy and financial ties with Russia.
The EU resisted Washington's calls to be firmer with Putin and on Wednesday only promised to add 11 new names to its list of 61 Russians and Ukrainian separatists targeted by travel and financial bans.
Moscow has shrugged off such measures and Russia's wobbly stock market has rebounded in the belief that EU leaders were too concerned about their own economies to unleash meaningful punitive steps.
Kiev for its part has largely ignored repeated attempts by French President Francois Hollande and German Chancellor Angela Merkel to resurrect a truce that Petro Poroshenko -- elected president in May on a vow to quickly reunite Ukraine -- abandoned on July 1.
"Formal negotiations with terrorists are impossible," deputy chief of staff Valeriy Chaly told reporters.
- Russian trade war -
The European Union hopes that some of the tensions with Russia can be lifted through talks over the terms of a historic June 27 free trade pact that opens the door to Ukraine's future membership in the bloc.
An abrupt decision by Ukraine's then Kremlin-backed government to ditch the agreement set off months of demonstrations and led to the ouster of president Viktor Yanukovych, setting off the separatist rebellion.
And with the new leaders' signature of the deal, Moscow has retaliated by nearly doubling the price of gas it supplies to Ukraine and threatening to set up devastating new trade barriers.
EU leaders now hope that a Friday meeting in Brussels with top Kiev and Moscow envoys can help wipe out some Russia's most immediate concerns about the June deal.