Ukraine's faltering peace deal suffered fresh setbacks on Saturday when Kiev reported the deaths of six soldiers and accused Moscow of abetting an attack on one of its Russian consulates.

The latest fatalities in the twisting and hotly disputed zone separating Ukrainian forces from their pro-Russian foes in the separatist east add to the strains of a February truce designed to end one of Europe's deadliest conflicts in decades.

The Pentagon is "poised" to station heavy weapons for up to 5,000 American troops in several Eastern European and Baltic countries to deter Russian aggression, The New York Times reported Saturday.

The proposal, if approved, would be the first time since the end of the Cold War that the U.S. has had heavy military equipment -- including battle tanks -- in newer NATO members that were once under Moscow's influence as part of the Soviet Union.

Ukraine's faltering peace agreement suffered fresh setbacks Saturday when Kiev reported the death of six soldiers and accused Moscow of abetting an attack on one of its Russian consulates.

The latest fatalities in the twisting and hotly disputed zone separating Ukrainian forces from their pro-Russian foes in the separatist east add to the strains of a February truce deal designed to end one of Europe's deadliest conflicts in decades.

Ukraine's premier warned Friday that Kiev would freeze its debt repayments if no immediate deal was found with private lenders because it had to fund its escalating campaign against pro-Russian fighters.

Prime Minister Arseniy Yatsenyuk said on his return from a crunch visit to Washington that the International Monetary Fund had given his embattled government a few weeks' reprieve to enact laws needed for the release of new loans.

The OSCE looks set to name an Austrian diplomat to replace Switzerland's Heidi Tagliavini as the security body's representative in peace talks over Ukraine, diplomats and press reports said Friday.

Envoys at Organization for Security and Co-operation in Europe headquarters in Vienna said that Martin Sajdik, currently Austria's ambassador to the United Nations, was in the frame for the job.

Washington's U.N. envoy accuses Russia on Thursday of spinning "outright lies" on Ukraine designed to hide the Kremlin's direct involvement in a war it launched to thwart Kiev's alliance with the West.

Samantha Power delivered an emotional address to a crowd of hundreds in Kiev designed to reassure pro-Western Ukrainians that Washington's backing of its decision to break most post-Soviet ties with Russia and join the European Union remained strong.

Russia on Thursday warned the United States of consequences if it moves to deploy land-based missiles in Europe in contravention of a key Cold-War era arms control treaty.

"It is clear that such actions would mean complete destruction by the American side of the regime of the treaty with all its attendant consequences," the Russian foreign ministry said, referring to the 1987 INF treaty on intermediate-range and shorter-range missiles.

Three Ukrainian civilians and two soldiers have been killed in the past day of intensifying clashes between the Western-backed government's forces and pro-Russian insurgents, officials from both sides said Thursday.

The eastern Donetsk region's self-proclaimed deputy defense minister Eduard Basurin told AFP that three women died when Ukrainian forces shelled Gorlivka, a rebel bastion about 30 kilometers (20 miles) northeast of Donetsk city.

Washington's U.N. ambassador met Wednesday with Ukraine's President Petro Poroshenko at a time of renewed hostilities with pro-Russian fighters and fears the Western-backed state was hurtling towards an imminent debt default.

Samantha Power's show of support for Poroshenko's embattled team will also see her speak to Foreign Minister Pavlo Klimkin and senior cabinet members. The avowed critic of Russia and promoter of the ex-Soviet state's budding alliance with Europe has scheduled a public appearance in Kiev for Thursday.

A majority of citizens from eight NATO countries are against sending arms to Ukraine to help battle pro-Russian separatists, even if they believe Moscow is stirring the conflict, according to a survey released Wednesday.

A majority of respondents in France, Germany and Italy also believe NATO should not use military force if Russia attacks another member state of the transatlantic military organization, according to the opinion poll conducted by the Pew Research Center.