Russian Foreign Minister Sergei Lavrov says the ceasefire in eastern Ukraine is being observed "in general" but "there are incidents when the sides blame each other".
He told a news conference today that Moscow hopes talks will soon start on the status of the Donetsk and Luhansk regions.
However, he raised concerns over the "heavy concentration" of Ukrainian troops in parts of eastern Ukraine.
Moscow has accused Washington of backing what it called the "party of war" in Kiev and said it was counting on a response from the leadership in Ukraine and rebels in its east to a Russian ceasefire plan.
Russia's foreign minister Sergei Lavrov has warned that Ukraine's bid to join Nato could "derail" the peace process in the east of the country.
Ukraine's government wants to join the defence alliance but some sections of its population, including its Russian-speaking minority, are opposed.
“This is an obvious attempt to derail all efforts to initiate a dialogue aimed at providing national security," Lavrov is quoted as saying by a Russian news agency.
Russia's Foreign Minister Sergei Lavrov has said the European Union should respect the results of the referendums in the Donetsk and Lugansk regions of Ukraine over the weekend.
Mr Lavrov's comments follow an apparently overwhelming victory for pro-Russian separatists, with rebel leaders claiming over 85% of voters in both regions voted in favour of independence from Ukraine.
The leader of the rebels in Donetsk has now reportedly asked for his region to be incorporated into the Russian Federation, though the Kremlin has yet to respond to the request.
Russia' Foreign Minister, Sergei Lavrov, has dismissed calls for a new round of international talks over Ukraine.
He said further negotiations would be "going round in circles" because the first agreement reached in Geneva has, in Russia's view, not been implemented.
Mr Lavrov also claimed it would be "unusual" for the Ukrainian presidential election to go ahead while the Ukrainian army is being deployed in the east of the country.
US and European Union sanctions on Russia over the Ukraine crisis are the result of the West's own weak policies, the Russian Foreign Minister has said.
Sergei Lavrov said Russia rejects sanctions "in any of our relationships, in particular those sanctions that were sponsored by the United States and the European Union, which are against all common sense, regarding the events in Ukraine".
Sergei Lavrov has told US Secretary of State John Kerry that Ukraine must stop its military operation in the country's southeastern as part of efforts to defuse the crisis, the Russian Foreign Ministry said.
In a telephone conversation with Kerry, Lavrov also urged the US to use its influence to secure the release of what the ministry called leaders of the "protest movement" in the region - a reference to pro-Russian separatists.
Russia's Foreign Minister Sergei Lavrov has said that Kiev's offer of dialogue with separatists in the east is a "step in the right direction, albeit very belated."
The official Twitter account of the Russian foreign ministry tweeted:
Russia and the United States exchanged strong-worded warnings over armed actions in Ukraine today.
Russian Foreign Minister Sergei Lavrov said that any armed action by Ukrainian authorities in the east of the country would undermine efforts at a diplomatic solution to the conflict.
Mr Lavrov made the warning during a call from US Secretary of State John Kerry, who in turn expressed concern about Russia's role in "inciting" trouble in eastern Ukraine, the Russian Foreign Ministry said in a statement.
The White House warned Russia against further military action in Ukraine after armed separatists seized government offices in the eastern city of Slaviansk today, saying the situation was reminiscent of what recently happened in Crimea.
Mr Lavrov said Ukraine was "demonstrating its inability to take responsibility for the fate of the country."He said that any use of force against Russian speakers in the east of Ukraine "would undermine the potential for cooperation."