Failure of US-Russia talks on Ukraine crisis disappointing: UK

British Foreign Secretary William Hague expressed his deep disappointment at the failure of US-Russia talks on solving the Ukraine crisis.

"It is deeply disappointing that today's talks did not produce the diplomatic breakthrough," Xinhua reported citing Hague's statement here Friday after the talks concluded in London.

No substantial agreement was reached between US Secretary of State John Kerry and his Russian counterpart Sergei Lavrov as both sides refused to back down from their previous stances towards Ukraine.

Though both leaders described their talks as "constructive", major disagreements remain largely unresolved, especially over the upcoming Sunday referendum in Crimea on whether the Ukrainian autonomous republic will join Russia or remain part of Ukraine.

He said the European Union (EU) foreign ministers will meet Monday in Brussels to discuss the next move, including the case for further sanctions against Russia.

"The United Kingdom is strongly of the view that there must be a firm and united response from the EU at the meeting of the Foreign Affairs Council Monday and that the time has come for tougher restrictive measures to be adopted as previously agreed by EU nations," he urged.

At the same time, Hague noted that the door remains open for "diplomacy and dialogue".