Dutch and Australian authorities put their troops on standby for deployment to secure the rebel-held crash site of Malaysian flight MH17 in east Ukraine, where fighting between the army and separatists Friday claimed over a dozen more lives.
The move came as politicians in Kiev were scrambling to avert a political crisis after the shock resignation of prime minister Arseniy Yatsenyuk, who quit in fury over the collapse of his ruling coalition on Thursday.
President Petro Poroshenko called on parliament to heed "cold reason" and pass a vote of confidence in the government, but lawmakers closed the sitting on Friday without taking a vote.
Yatsenyuk's resignation piles on more woes for a country already struggling to cope with a chaotic situation in the rebel-controlled east, where international experts are carrying out a complex investigation into last week's downing of Malaysia Airlines flight MH17 that killed 298 people.
The grave challenges facing Ukraine, where 230,000 people have fled fighting according to the United Nations, go beyond its borders, as Washington accused Russian troops of firing artillery across the border on Ukrainian forces.
The United States has already accused Moscow of supplying the missile system it believes was used by pro-Russian separatists in east Ukraine to shoot down MH17. It said late Thursday it had evidence that Russia was planning to "deliver heavier and more powerful multiple rocket launchers" to the insurgents.
Both Russia and the rebels deny the accusations, and Moscow hit back Friday, dismissing the US claims as a "smear campaign".
- 'Bring them home' -
A truce has been declared in the vicinity of the vast crash site in rebel-held Grabove, where experts say some remains of the victims still lay decomposing under the sweltering summer heat more than a week after the tragedy.
Dutch authorities said 189 coffins have been flown to the Netherlands where the remains would be identified, with another flight set to carry 38 more from the eastern Ukrainian city of Kharkiv to Eindhoven on Saturday.
Foreign ministers from the Netherlands and Australia attended a ceremony at Kharkiv airport, as both countries said they are seeking to deploy troops to the site.
The Netherlands, which is leading the probe after losing 193 citizens in the crash, said troops had been consigned to barracks and had leave cancelled ahead of a possible mission to secure the site.
Australia, which lost 28 people, said it already has 90 police in Europe ready to deploy and that it also plans to send troops.
"This is a humanitarian mission with a clear and simple objective: to bring them home," Prime Minister Tony Abbott said. "All we want to do is to claim our dead and to bring them home."
But monitors from the Organisation for Security and Cooperation in Europe said rebels controlling the area were only ready to accept between 25 to 35 members of foreign delegations.
As the scramble to salvage the victims dragged on the impact of the crash continued to reverberate across the globe, and the UN's International Civil Aviation Organization (ICAO) called together world aviation officials for a high-level meeting Tuesday to discuss lessons learnt from the incident.
- 'Second front' -
The government's offensive to regain control of Ukraine's eastern industrial heartland was given a boost Friday when its forces took the strategically-important city of Lysychansk.
At the same time, it reported losing 13 soldiers in the past 24 hours, while local authorities in the region of rebel strongholds of Donetsk and Lugansk said 16 people have been killed.
The bloody insurgency has forced 230,000 people to flee their homes, the United Nations said, including 130,000 who have sought refuge in Russia.
While the civil war rages on in the east, politicians in Kiev were locked in a fierce debate over Yatsenyuk's abrupt resignation, with the UDAR (Punch) party of boxing champion Vitali Klitschko insisting that the premier stay on until early parliamentary elections are held.
Together with a few other parties, UDAR announced Thursday it was leaving the governing coalition -- a move that sparked Yatsenyuk's resignation and appeared to fire the starting gun for a rancorous campaign ahead of possible legislative polls expected this fall.
The political uncertainty prompted Christine Lagarde, the head of the International Monetary Fund -- which in late April approved a $17 billion two-year financial lifeline for Ukraine -- to telephone Poroshenko and Yatsenyuk.
"The discussions focused on the implications of the recent political developments in Ukraine for economic policies, in particular for the authorities' ability to implement the programme that is being supported by a Stand-By Arrangement," the IMF said.
Lagarde "encouraged steady implementation of the authorities' reform programme", said the Fund, which had previously forecasted that Ukraine's economy would contract by 6.5 percent this year due to the insurgency engulfing the country's vital industrial east.
The Fatherland faction of ex-prime minister Yulia Tymoshenko condemned the coalition's collapse, saying it "opens up a second front" in the country as it battles to quell the insurgency in the east.
"Between peace and chaos, Ukraine unfortunately is choosing political chaos," said the party in a statement read out by one of its lawmakers in parliament.