[caption id="attachment_50688" align="aligncenter" width="553" caption="U.S. paratroopers arrived for training exercises with the Polish army in Swidwin, Poland"][/caption]

Russia warned on Wednesday that any attack on its citizens in Ukraine would be considered an attack on Russia itself, as the Ukrainian government said it had resumed its "antiterrorist" operation against pro-Russian militants in the eastern part of the country. The escalating rhetoric comes amid growing signs that the agreement reached last week in Geneva between the U.S., European Union, Russia and Ukraine, laying out steps to reduce tension, was headed for failure. Its collapse would escalate a race between Washington and Moscow to fix blame on the other side—as well as set off new rounds of tit-for-tat punitive measures.

Setting the stage for likely new sanctions, the State Department said that Russia's recent public comments have been devoid of "any indication of a plan to implement the Geneva statement, to follow through on promises made." Western capitals and Ukraine accuse Moscow of failing to rein in the pro-Russia, anti-Kiev groups in eastern Ukraine. Russia's Foreign Ministry, meanwhile, blasted Ukraine and the U.S. for what it called a "distorted interpretation" of the Geneva deal, arguing that Kiev isn't doing enough to disarm and rein in Ukrainian nationalist groups. Washington and Kiev reject those allegations. Poland on Wednesday welcomed some 150 U.S. troops to its territory, sent to reassure American allies close to the Russian border. U.S. officials said the Obama administration was moving rapidly toward imposing new sanctions on more people close to President Vladimir Putin within days, fueling expectations of action by Friday. More Videos The Pentagon said U.S. troops would be sent for exercises in Eastern Europe to reassure allies on Russia's border, after Ukraine accused pro-Russian separatists of killing two people and shooting at a military plane. Julian Barnes reports. Photo: AP. Pro-Russian forces in eastern Ukraine say they aren't taking acting President Turchynov's threats seriously. They continue to occupy government buildings despite yesterday's order for security forces to resume antiterrorist operations in the region. The White House had initially planned to impose new sanctions on Russia last week, but held off after Russian Foreign Minister Sergei Lavrov signed the Geneva deal, according to two American officials who took part in the talks last Thursday.

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