Putin denies Ukraine protest claims
The Kremlin said in a statement following today's conversation that the Russian leader rejected the claims of Russian agents' involvement in protests as "speculations based on unreliable information".
Mr Putin said the protests vented public anger about the Ukrainian government's reluctance to recognise the interests of Russian speakers in the east.
More than a dozen government offices and police stations have been seized by mobs. The Ukrainian government and the West have accused Russia of staging the protests.
The Ukrainian authorities have pledged to dislodge protesters.
The Kremlin said Mr Putin urged Mr Obama to use American influence in Ukraine to prevent the use of force and bloodshed.