The US takes a 'wait and see' approach after Ukraine elects a new president Petro Poroshenko. President Barack Obama has been among the first to congratulate Ukraine's newly elected president.
But having become frustrated with Moscow's support of the separatists in eastern Ukraine, Washington is now taking a more cautious approach.
However, US foreign policy experts such as John Herbst, who is a former US ambassador to Ukraine, are more outspoken.
'If Ukraine decides that it would like to be a member of the EU and not a member of NATO, that's fine. If it decides it does not want to be a member of the EU or NATO, that's fine. But what is not fine is for Russia to use its military, for Russia to use an insurgency and for Russia to use economic pressure to insist that Ukraine make a choice that the Kremlin wants. That's completely unacceptable.'
Other experts including former US National Security advisor Zbigniew Brzezinski warn that Russia would be foolish to let things get out of hand:
'If Putin thinks of Russia's longer-range interests, he would have to reach the conclusion that a Russia that has good relations with the West including with Ukraine is a Russia that will thrive much more than if it is isolated in creating a Eurasian empire.'
From Washington, our correspondent Stefan Grobe said:
'There are some concerns in Washington's foreign policy community that Ukraine might turn into a Somalia-type of hot spot, as President-elect Poroshenko has pledged he would not allow to happen. The Obama administration has adopted a wait-and-see attitude, knowing that the key to the conflict lies in Moscow.'
Illustration: Ukrainian stamps