Kirovske (Ukraine) (AFP) - US President Barack Obama told Russia's leader Friday of his "deep concerns" about Moscow's increased support for separatists in Ukraine as international experts finally gathered more remains at the downed MH17 flight's crash site.
In a telephone call with Russian President Vladimir Putin Obama also expressed "his preference for a diplomatic solution to the crisis," the White House said.
Separately, the Kremlin said the two leaders had agreed that the current standoff in Ukraine -- where pro-Russian rebels are battling government forces -- was "not in the interest of either country."
The tragedy of the Malaysia Airlines plane which was downed two weeks ago killing all 298 people on board has again focused world attention on the conflict in Ukraine.
Seventy police investigators -- by far the largest number to reach the location so far -- finally managed to comb the scattered wreckage in the fields in eastern Ukraine on Friday.
More than 220 coffins have been sent back to the Netherlands, which lost 193 citizens in the July 17 crash. The United States says the pro-Russian rebels likely shot down the plane with a missile supplied from Russia, but Moscow and the insurgents contend the aircraft could have been brought down by a Ukrainian fighter jet.
"We are happy that we can make sure that these remains can now be sent," said Pieter-Jaap Aalbersberg, the Dutch police official sent to Ukraine to head up the mission there.
"We hope that this can bring comfort to the bereaved. It is a relief that our people are now at work," he said, adding later that the "very difficult" searches would take "at least several weeks".
The observer mission for the Organization for Security and Cooperation in Europe (OSCE) called Friday "the biggest day" yet at the crash site as experts were able to recover several remains and passengers' belongings.
Despite the international team managing to begin work at the site the fighting that had impeded their probe continued to rage across eastern Ukraine.
The Ukrainian military said an overnight ambush by insurgents in Shakhtarsk, a town 25 kilometres (15 miles) from the main impact site, left 14 people dead, including at least 10 soldiers.
Thirteen more soldiers were injured and another 11 were missing as fighting wore on, the military said.
An AFP team some 12 kilometres from the MH17 site heard the sound of tank fire and saw smoke rising from the direction of Shakhtarsk.
- Call to halt fighting -
Both rebels and Kiev have vowed to keep open an access corridor to the crash site, while Ukraine's army has pledged not to fight in the immediate vicinity.
Elsewhere around the region though, government forces relaunched their offensive to oust the separatists, after a "day of quiet" brought a brief pause to over three months of fighting that has cost the lives of more than 1,100 people on the ground.
The Kremlin said Putin and Obama had agreed on the urgent need for an "immediate and stable halt to fighting in southeast Ukraine and the start of a political process".
The Ukrainian military claims it is getting close to cutting off the main rebel stronghold of Donetsk from the Russian border and the second insurgent bastion of Lugansk, saying it took the village of Novyi Svit, some 25 kilometres southeast of the industrial hub.
Fighting also flared in Donetsk, which serves as the base for the international police and journalists trying to reach the MH17 site some 60 kilometres away, with local authorities saying one civilian died after a minibus taxi was hit by mortar shrapnel.
In Lugansk, officials said five civilians were killed and nine injured in clashes over the past 24 hours.
- Early elections pledge -
Meanwhile Ukrainian President Petro Poroshenko pledged that the strife-torn nation would have a new parliament in place in the next few months, confirming that he intends to call long-awaited legislative polls.
"In autumn there will be a new parliament that will start on reforms," Poroshenko said in a televised interview.
The fresh fighting on the ground entrenched a crisis that has pushed East-West tensions to their highest point since the Cold War. The EU and US have hit Russia with the most punitive measures since the collapse of the Communist bloc over its backing for the rebels.
Putin made his first comments on the latest tougher sanctions imposed this week by the United States and European Union against Russia in the phone call with Obama.
Putin characterised them as "counterproductive, causing serious damage to bilateral cooperation and international stability overall," the Kremlin said.