Leading Ukrainian politician Yulia Tymoshenko has called for Europe to take strong action over Crimea's attempt to join Russia, warning that otherwise Moscow would move to take over the rest of Ukraine and destabilise the continent.
"If we allow Russia on March 16 to hold a referendum at gunpoint, on the annexation of Crimea, we will lose Ukraine, we will lose not only Ukraine but stability in the whole world"; Tymoshenko said.
Ukraine opposition leader Vitali Klitschko, who joined her at a conference in Ireland, said he was hopeful for the future of his homeland.
"We are European geographically, historically and mentally also European, unfortunately we are far away from European standards of living. Despite all of that, we are hopeful and we want to become part of Europe", he said.
Ukrainian politician and likely presidential candidate Vitali Klitschko has called for a "general mobilisation" following the Russian parliament's decision to approve deploying troops in Ukraine's Crimea region.
Vitali Klitschko says it is a "mistake" for Russia to help former president Victor Yanukovich.
Asked about a press conference the former president is due to hold in Russia later he told ITV News:
"I think it's a mistake for the Russian Federation to help a man like that. A man who shot his people and held all the power.
"Yanukovich has to take responsibility for what has happened in this country. We have a huge political and economic crisis as a result of four years of his rule. He promised to listen to the people and he did not. It's all a result of his total corruption in Ukraine.
"People don't have justice and right now everyone is very upset. People want change. Everyone hopes we can change our country.
"We see right now the result of his power. I told him personally to step back months ago. If he had done that we wouldn't have the huge political crisis we have now in Ukraine."
Mr Klitschko, who will stand in the presidential elections in May, told ITV News this morning:
"The situation in Crimea is very critical. It is difficult to understand why Russia has sent a Government representative to Crimea but we are doing everything we can to keep the situation under control.
"There is a risk the situation could spread and dealing with that is the main task for politicians in Parliament today and also should be for politicians around Europe. We have to let the politicians try and sort this out not the police or military people."