Ukraine's ambassador to the UK has spoken of the feeling of hopelessness and trepidation felt by his countrymen, and their disbelief at a neighbouring invasion "in the 21st century."
Volodymyr Khandogiy, Kiev's ambassador in London told the BBC's John Humphyrs that he knew it was "a problem" that Ukraine was not in a position to make demands on Russia, and that the country could simply ignore any insistence the country makes that troops leave Crimea.
"It is a problem," the ambassador conceded. "Realistically I am not optimistic. I think the situation is pretty tough, pretty difficult and very worrisome.
"We need a politically settlement, but we are not excluding other measures."
A peaceful solution, ultimately he said "all depends on the Russians".
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"I do view the future with some trepidation. As a Ukrainian, as a citizen of the country, I cannot comprehend why in the middle of the 21st century we are facing an invasion. An invasion like this, from our big neighbour."
Ukraine, he said, "cannot accept, even theoretically, the annexation of Crimea".
"It has not happened yet. I disagree it has been effectively been annexed already," he continued. |It is occupied. There is a Russian Black Sea fleet which has the right to be stationed in Crimea, in a very specific location. So what we demand is they remove all the forces, back to the place they are supposed to be location, and withdraw all external forces. The Russians have to calculate whether this is in their interests."
The UK and US have urged Moscow to order troops which have seized key military and administrative locations in the Crimea back to their barracks and to allow the deployment of international observers from the Organisation of Security and Co-operation in Europe to the southern peninsula, which is part of Ukraine but is home to Russia's Black Sea fleet, under an agreement signed in 1997.
But speaking in Madrid en route to Paris, Russian Foreign Minister Sergei Lavrov repeated president Vladimir Putin's denial that the soldiers operating in uniforms without insignia were Russian troops, or under Moscow's control.
Troops of the Black Sea fleet had stepped up security around Russian military facilities in Crimea but had not deployed outside their bases, he said.
The decision on whether monitors should be admitted was not for the Kremlin, but for the "supreme Soviet" of Crimea as well as the government in Kiev, which Mr Lavrov said was not in control of the largely Russian-speaking peninsula.
"It is clear that those who sit in the Ukraine parliament do not control the entire territory of the country - in the Crimea, for instance, and in other areas where people do not want to recognise the legitimacy of those who came to power in an unconstitutional way," said Lavrov.
"You should be talking to the people who control the situation in the Crimea, to their supreme Soviet. If they would want to invite international monitors and if the government in Kiev would do the same, that would be the decision of Ukraine."