Ukraine's interim leaders are battling to keep the country together for the May 25 vote in the face of a bloody insurrection in the east and a tense standoff with former master Russia.
Kiev yesterday hosted the first round of so-called national unity talks under an OSCE initiative to try to resolve the crisis on Europe's eastern flank and allow the vote to go ahead.
Crucially however, the pro-Moscow rebels fighting against Kiev's rule in the industrial east of the country were not at the table, despite Western calls for inclusive talks.
President Barack Obama has already drafted an executive order to impose sanctions across key sectors such as banking, energy, defence and mining, adding to punitive measures already imposed by Washington and Brussels.
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"There are a lot of things we can do to create bleeding," the official said, adding that the aim was "to use a scalpel rather than a hammer".
"We will not yield to blackmail," he said. "We are ready to listen to the people of the east but they must not shoot, loot or occupy government buildings."
Without the rebels there was no progress reported at the Kiev talks, but the US official said Ukrainians were working to hold another round in the restive east on Monday.
Western leaders see the May 25 vote as crucial for the future of Ukraine after Russia's much criticised annexation of Crimea in March, which plunged relations between Moscow and the West to their lowest point since the Cold War.