Kiev: Crisis-hit Ukraine won a vital reprieve from Russia on Monday when Moscow pushed back until next week a possible cut in gas shipments that would also impact parts of Europe.
But the seven-week insurgency in its eastern rust belt continued unabated when several hundred pro-Russian gunmen used mortar and grenade launchers to attack a Ukrainian border guard unit outside the rebel stronghold city of Lugansk.
The border force said seven guards were wounded and five separatist rebels killed when Ukraine used fighter bombers to repel a dawn raid that was still raging on Monday afternoon.
Russia`s surprise gas decision came hours before the two sides were to lock horns in Brussels over a price dispute that emerged when Moscow cancelled the discounts it awarded pro-Kremlin leader Viktor Yanukovych prior to his February fall.
Moscow had threatened to halt all shipments to Ukraine -- a vital gas transit nation now seeking a closer alliance with the West -- from Tuesday in a repetition of interruptions that also hurt swathes of Europe in 2006 and 2009.
A visit to Kiev by US Assistant Secretary of Defence Derek Chollet marked another vital boost for Ukraine as it seeks to build international pressure against attempts by a part of its economically vital industrial east to join Russia.
Downing Street said that British Prime Minister David Cameron would also press Russian President Vladimir Putin to take immediate steps to de-escalate Europe`s worst crisis in decades when the two leaders meet on the sidelines of Friday`s D-Day commemorations in Normandy.
"It is an important opportunity to set out the importance of a dialogue between the Russian government and the new Ukrainian government following the presidential elections... in Ukraine," Cameron`s official spokesman said.
But a Kremlin spokesman said the question of Putin`s first meeting with Petro Poroshenko "is not being worked upon" despite the Ukrainian president-elect`s promise to arrange such talks in Normandy.
Putin has not officially spoken to any Kiev official since Ukraine chose to anchor its future to Europe following the pro-Kremlin regime`s overthrow. Russia`s state-run gas giant Gazprom -- long accused of acting as the Kremlin`s political enforcer against neighbours seeking closer ties to the West -- said it "welcomed" Ukraine`s decision to transfer a $786-million payment (576-million-euro) to partially cover its debts.
"We welcome Ukraine starting to pay back its debt and postpone the pre-payment regime until June 9," Gazprom chief executive Alexei Miller said in a statement."
Gazprom had said it would halt all shipments to Ukraine unless it paid for June deliveries by Monday night.
Ukraine had branded Gazprom`s decision to nearly double its gas price a form of "economic aggression" and balked at Russia`s demand for advance payments for deliveries starting in June.
Russian gas transits through Ukraine supply about 15 percent of European needs and a top EU envoy is now urgently seeking a compromise that could save 18 member states from seeing their deliveries start to dwindle as early as next week.
Analysts believe a long-term solution was possible because Russia would prefer to avoid complicating its relations with Europe amid US threats to impose wider economic sanctions for its perceived involvement in the eastern insurgency.Ukraine`s president-elect Poroshenko -- a charismatic confectionery tycoon who scored a crushing victory in a May 25 election and refuses to recognise Russia`s March annexation of Crimea -- is seeking a closer Western military alliance that could protect his splintered country`s sovereignty.
The visit by the Pentagon`s Chollet comes ahead of Poroshenko`s first meeting on Wednesday in Warsaw with US President Barack Obama.
Ukraine and the ex-Soviet satellites of eastern Europe are anxious about the impact of a big speech Obama gave last week in which he put American diplomacy above military might in confronting threats such as that of Russia`s expansion.
But US officials insist that Washington`s commitment to Ukraine remained strong.
Chollet said after talks with Ukraine`s acting defence minister that Washington was in discussions on providing $18 million (13 million euros) in military assistance and helping Kiev "build highly effective armed forces" -- comments that are sure to irk the Kremlin.Putin spelt out the threat of an outright invasion of Ukraine when he sought and won parliament`s authorisation on March 1 to use any means necessary to "protect" his compatriots living across the border.
But the drumbeats of war began fading last month when Putin surprised many with a sudden softening of his tone.
The Russian leader advised Ukraine`s eastern Lugansk and Donetsk regions against holding May 11 independence referendums that went ahead anyway but which he then refused to recognise as binding.
Putin also promised to "respect" the outcome of Ukraine`s own election and began pulling back the 40,000 troops he had parked just inside Russia`s border in an ominous show of strength that touched off near-panic in Kiev.
Western diplomats remain sceptical about the sincerity of Putin`s restraint.
Russia piled further diplomatic pressure on Kiev by saying it would on Monday submit a draft resolution to the UN Security Council on creating a corridor to allow civilians to escape areas affected by the fighting.
Ukraine has previously rejected the need for such an "aid corridor" out of fear that Russia might want to send in troops to supervise the evacuation.