High-level talks in London aimed at solving the crisis in Ukraine have ended without agreement. The United States says it is strongly against a referendum this weekend in the Crimea region, where voters will decide whether to join Russia.
US Secretary of State John Kerry met his Russian counterpart Sergei Lavrov for critical talks aimed at resolving the crisis in Ukraine.
It came as the West warned of sanctions including asset freezes and travel bans unless a planned vote on the southern region of Crimea breaking away to join Russia is called off.
Mr. Kerry has warned of "very serious steps" from the US and European Union if the referendum goes ahead in the Black Sea peninsula, which has close links to Moscow.
The vote is expected to back the splitting off of the region, where the majority of people speak Russian. Western powers have already indicated they will not recognise the outcome of Sunday's Crimean vote, which they consider illegal.
But US President Barack Obama said he still hoped a diplomatic solution could be found to the crisis.
The Russian Foreign Minister admitted the crisis over Crimea was a "very difficult situation." But speaking through a translator, Sergei Lavrov insisted the position of Moscow is clear.
Speaking before the talks, Mr. Kerry said he hoped the talks being held in the US Ambassador's residence in Regent's Park would "resolve some of the differences between us".
He added "Obviously we have a lot to talk about and look forward to an opportunity to dig in to the issues and possibilities that we may be able to find about how to move forward together to resolve some of the differences between us. We look forward, I know, to a good conversation" he added.
And tensions appeared to surface even during the introductory remarks when Mr. Kerry's interpreter jumped in to provide a Russian translation of his comments to the obvious annoyance of Mr. Lavrov's own translator.
The British Foreign Secretary William Hague had said it will be "formidably difficult" for Mr. Kerry and Mr. Lavrov to make progress on defusing the Ukraine crisis.
John Kerry & Sergei Lavrov seen during their talks in London
Speaking after holding separate talks with both men, Mr. Hague said he believed they were "seriously committed" to finding a way forward during face-to-face discussions.
"But the fact that so far Russia has not taken any actual action to de-escalate the tensions makes this a formidably difficult task today," Mr. Hague said.
The Crimea vote on Sunday is "deeply unhelpful", and had set a "diplomatic deadline" he believed. Mr. Hague added "This is a referendum which doesn't meet any international norms or standards".
EU Foreign Ministers will meet in Brussels on Monday to discuss sanctions.
It is understood that EU ambassadors are meeting in secret session where a list is being drawn up of individuals who could be targeted by sanctions. However, the Russian state oil company Rosneft has said a visa ban on its chief executive would be "stupid" and hurt Western firms more.
Russia claims Ukraine has 'lost control'
Meanwhile tensions continue to run high in Ukraine, with clashes in the divided east of the country which left at least on person dead. Russia said it showed the Ukrainian authorities had lost control and that it reserved the right to protect its "compatriots" there.
Pro-Moscow authorities in Crimea says the region could join Russia within a year of the referendum.
It also said the Ukrainian energy firm Chornomornaftohaz could be sold to a Russian company "like Gazprom" once the regional authorities take control of it.
Moscow, which does not recognise the new interim administration in Kiev, has so far ignored the threat of sanctions designed to force it to pull back from Crimea, which is home to its Black Sea fleet.
The operation by Russia to seize Crimea began within days of Ukraine's pro-Kremlin president Viktor Yanukovych being forced from office, after three months of demonstrations against a decision to ditch closer ties with the European Union in favour of Russia.
