Russia declared today that its military is massed on Ukraine's doorstep and warned against further US sanctions as a deal it had struck with Washington appeared to stall because of intransigence by rebels it backs in the former Soviet republic.
A threat by US President Barack Obama that more sanctions would befall Moscow if the agreement, reached yesterday with Ukraine and the EU, failed was "absolutely unacceptable," Kremlin spokesman Dmitry Peskov told Russian television.
"Our Western colleagues are trying to push responsibility towards our side. But it must be underlined: it is a collective responsibility," he said.
He pointedly declared that "there are troops close to the Ukrainian border". "Some are based there, others have been sent as reinforcements due to the situation in Ukraine," he added.
The comments appeared to be a warning shot to Washington that the situation could quickly degrade if Moscow were punished for a failed implementation of the accord.
The White House reiterated that it was watching Moscow to see if it is holding up its end of the deal.
"We expect and we will be watching whether Russia does or does not uphold its responsibility to use its very considerable influence to restrain and withdraw those irregular militia from the buildings and spaces that they've occupied," said National Security Advisory Susan Rice.
Her colleague at the State Department, spokeswoman Jen Psaki added: "If they don't take steps, there will be consequences."
The agreement included a call on "all illegal armed groups" to disarm and leave seized state buildings and squares.
But on the ground in Ukraine's restive east, there were signs the pact was coming unstuck hours after the four parties signed off on it.
Pro-Russian rebels were stubbornly refusing to cede control of a string of towns they seized over the past two weeks.
But, says Moscow, neither are pro-Western protesters in Kiev budging from the iconic Maidan square they continue to occupy even after ousting former president Viktor Yanukovych two months ago.
"One cannot treat Russia like it is a shameful student, and brandish a piece of paper on which we put crosses next to the duties it has accomplished," said Peskov.
If the hard-won agreement collapses -- as Western and Ukrainian leaders fear it might -- the United States has said it will quickly ramp up sanctions on Russia, which it holds responsible for supporting the separatists and stoking the crisis.
