Ukraine crisis: Kiev reaches out to eastern rebels
Ukraine's interim authorities have appealed for national unity and promised to meet some of the demands of pro-Russian protesters in the east of the country.
These include the decentralisation of power and guarantees for the status of the Russian language.
The move came after pro-Russian activists and militias refused to vacate buildings they have taken over.
This was despite Thursday's deal on ending illegal occupations.
At talks in Geneva, Russia, Ukraine, the EU and US agreed that illegal military groups in Ukraine must leave official buildings, and that there should be an amnesty for anti-government protesters.
But protest leaders occupying government buildings in eastern cities such as Donetsk said the interim authorities in Kiev must step down first, as they had taken power in what they said was an illegal coup.
In a joint televised address to the nation with interim Prime Minister Arseniy Yatsenyuk, acting President Olexander Turchynov said the Russian language could be granted official status alongside Ukrainian in regions where it was spoken by a majority of the population.
He said the decision had been taken to help reach "peace and accord among the citizens of Ukraine".
The two men also said they would support wider constitutional change, including decentralising more power to local government, and urged people to refrain from violence.
Earlier, Alexander Gnezdilov, spokesman for the self-proclaimed Donetsk People's Republic, said his group would evacuate the government building in the eastern city only when the "illegal" Kiev government vacated parliament and the presidential administration.
Another protest leader in Donetsk said the separatists would not leave unless pro-European Union demonstrators in Kiev's Maidan Square - the vanguard of the protest movement that toppled President Viktor Yanukovych, an ally of Moscow - packed up their camp first.
A statement from the Donetsk separatists said "we cannot accept the values of the Kiev junta, we have our heroic past going back to World War Two, we are the Russian bear which is waking up".
It added: "Don't worry, everything will stay peaceful and orderly. The only problem is if the Kiev junta want war."
Their comments were rejected by a US state department spokeswoman, who said there was a difference between illegal armed occupations by separatists in eastern Ukraine and "legal and peaceful" protests in Maidan Square.
She said: "We see a strong connection with Russia here", adding that the Russian government had a responsibility to encourage the separatists to stand down.
Russia hits back at US
US President Barack Obama has warned that the US and its allies are ready to impose new sanctions on Russia - accused by the West of supporting the Ukrainian separatists - if the situation failed to improve.
The Russian foreign ministry responded by saying it was disappointed with the US assessment of the Geneva deal, describing the threat of fresh sanctions against Moscow as "completely unacceptable".
In a statement issued on Friday, the foreign ministry also accused US officials of seeking to "whitewash" what it said was the use of force by the Kiev authorities against protesters in eastern Ukraine.
In other developments on Friday:
- The interior ministry in Kiev issued an arrest warrant for Olexander Yanukovych, the eldest son of fugitive ex-President Yanukovych and a millionaire businessman, for alleged forgery of documents; the ex-president fled to Russia in February - it is not clear where he or Olexander are now
- Russia demanded that Kiev explain an official notice restricting entry to Ukraine for most Russian men aged between 16 and 60.
Speaking to the BBC, UK Foreign Secretary William Hague said: "We really want to see over the next few days, everybody - Russia included - using their influence, acting in good faith on the basis of the agreement.
"We can't be sure, given past performance, that Russia will implement every aspect of this deal, but we will do everything possible both to assist them to do so, through the work of the international monitors - and to make clear to them, if it is not implemented, there is more economic pressure, most definitely, on the way."
Ukraine has been in crisis since President Yanukovych was toppled in February.
Russia then annexed the Crimean peninsula - part of Ukraine but with a Russian-speaking majority - in a move that provoked international outrage.