Sunday's presidential election in Ukraine will deepen political divisions in the country if there is no end to hostilities and a "road map" to end the crisis is not implemented, a senior Russian official was quoted as saying on Tuesday.
Deputy Foreign Minister Grigory Karasin's remarks were the latest from Moscow to cast doubt on whether Russia will consider the election legitimate.
In a report on talks between Karasin and British ambassador to Russia Tim Barrow, the Foreign Ministry underlined the importance of the "road map" drawn up by the Organization for Security and Cooperation in Europe (OSCE) and constitutional reforms following an agreement reached at talks in Geneva.
"Without the implementation of these agreements, and the immediate cessation of hostilities by (Ukrainian) army units southeastern regions, the May 25 election can only worsen the differences in the country," the ministry said.
At the talks in Geneva, the United States, Russia, Ukraine and the European Union agreed moves to ease tensions in Ukraine,
following Russia's annexation of the Crimean peninsula and the seizure of buildings in the east by pro-Russian forces.
President Vladimir Putin has said Sunday's election could be "a step in the right direction" but other Russian officials have signaled Moscow may not recognize the outcome, especially if Kiev continues to use the armed forces in eastern Ukraine.
The pro-Western authorities in Kiev, who are not recognized by Moscow, have deployed military and security forces in the east to try to regain control of buildings seized by the pro-Russian separatists.
The Russian Foreign Ministry said these operations "block any real steps towards de-escalation of the situation".
Russia also wants constitutional reforms to give more autonomy to mainly Russian-speaking regions in the east.
Reporting by Vladimir Soldatkin and Timothy Heritage, Editing by Steve Gutterman