Talks between world leaders and members of the Ukraine government will resume before midday today.
World leaders were last night engaged in frantic efforts to stabilise Ukraine with a "road map" for peace after the deaths of dozens of protesters plunged the country's political crisis to new depths.
The talks finished at 5.45am Irish time this morning, and are expected to resume before midday today.
The discussions, which were being brokered by three European Union ministers, are proving difficult, a European diplomatic source said.
"The negotiations are very difficult and went on all through the night," the source said. "There is a break now. The participants will come back together again before midday."
A tentative truce brokered overnight on Wednesday was shattered yesterday as demonstrators reported that government snipers had opened fire on crowds in the capital, Kiev.
As many as 70 are reported to have been killed and the death toll was last night expected to rise further.
Russia and Europe dispatched envoys to Kiev in an attempt to stop the bloodshed escalating. With smoke from burning barricades drifting across the city centre, the foreign ministers of France, Germany and Poland held crisis talks with the president, Viktor Yanukovych, and opposition leaders.
Last night their efforts appeared to bear fruit after Mr Yanukovych was reported to be showing "a willingness" to call early elections to end the crisis.
The Polish prime minister, Donald Tusk, told a news conference: "Three ministers are in Kiev discussing a certain document, which gives a chance to bring an end to violence and achieve an agreement. A willingness for early elections, already this year, parliamentary as well as presidential, was agreed."
The European Union voted on Thursday to impose sanctions against those who are held responsible for the violence in Ukraine.
The sanctions, unanimously approved by EU foreign ministers at an emergency meeting, include a travel ban to the 28-nation bloc and the freezing of assets held in EU countries.
Tanaiste Eamon Gilmore agreed there was a need for action in response to the events in Ukraine.
"I do believe that we need to take action," he said, speaking in Brussels. "The sanctions will target "those responsible for human rights violations, violence and use of excessive force" in Ukraine, the EU said in a statement.
It said the bloc will soon establish a list of those who will be affected by the sanctions.
In London, Downing Street said the British prime minister David Cameron had called the Russian president, Vladimir Putin, who had dispatched an envoy at Mr Yanukovych's request to mediate in talks with the opposition.
A spokesman said: "The Prime Minister agreed with President Putin that they should both encourage all sides in Ukraine to get behind this emerging plan as a way to end the violence and open the way to a lasting peaceful solution."
Despite the frantic diplomatic activity, the statements emanating from Europe and Russia laid clear the bitter political divisions that risk tearing Ukraine apart.
In Brussels, the 28 nations of the European Union agreed to impose "targeted" sanctions on Ukrainian security officials accused of allowing police to shoot at protesters. This followed Washington imposing US visa bans on 20 government officials for "human rights abuses". Russia openly criticised the EU and US measures, calling them "blackmail".
Dmitry Medvedev, the Russian prime minister, contradicted the EU pleas for Mr Yanukovych to desist from using force against the protesters, saying the Kiev government risked looking weak.
"We need partners who are in good shape and for the authorities that work in Ukraine to be legitimate and effective, so that people don't wipe their feet on the authorities like a doormat," Mr Medvedev said.
This week's clashes have been the deadliest since the anti-government protests started three months ago, prompted by Mr Yanukovych shelving an EU trade agreement in favour of closer ties with Russia.
Last night there were signs Mr Yanukovych was losing support from his own side. The chief of Kiev's city administration, Volodymyr Makeyenko, said that because of the violence, he was leaving Mr Yanukovych's pro-Moscow Party of Regions.
"This is our only chance to save people's lives," he said. Another influential member of the ruling party, Serhiy Tyhipko, said both Mr Yanukovych and opposition leaders had "completely lost control of the situation". At the Winter Olympics in Sochi, the Ukrainian alpine skier Bogdana Matsotska, 24, withdrew from tomorrow's women's slalom in protest at the killings and "the lack of responsibility from the side of the president and his lackey government", her father and coach, Oleg Matsotskyy, wrote in a Facebook post.
Mr Yanukovych insisted those policing the demonstrations were not armed and that "all measures to stop bloodshed and confrontation are being taken". The Interior Ministry issued a decree granting police officers the right to use live ammunition and warned Kiev residents to limit their movements or stay home altogether because of the "armed and aggressive mood of the people."
The ministry admitted deploying snipers, saying they were providing covering fire for officers who came under fire from armed protesters.
It says 410 officers have been admitted to hospital and 13 killed since fighting started on Tuesday. (© Daily Telegraph, London)
Roland Oliphant, Kiev
The Ukrainian President faced intense diplomatic pressure from both East and West yesterday, after the European Union finally agreed on sanctions to try to stop the bloodshed in Independence Square, even as Moscow implied Kiev should take a heavier hand with protesters.
As Kiev burns, Western policymakers are eating ashes. Our efforts to help Ukraine towards Europe, democracy and the rule of the law have failed spectacularly. Meanwhile, Russian President Vladimir Putin is celebrating not just sporting triumph in Sochi, but geopolitical victory in the affairs of his most important neighbour.