"Vladimir Putin stressed that a genuine cessation of fighting and the start of direct talks between the warring sides would have the highest priority for the normalisation of the situation in the southeastern regions," the Kremlin said in a statement following the phone talks.
"The importance of (finding) an immediate solution to humanitarian issues including urgent assistance to the war-affected civilians was also stressed," said the statement, noting that the two leaders also discussed Ukrainian President Petro Poroshenko's peace plan announced on Friday.
Separately, Putin and Obama expressed "serious concern" over the advances of jihadists from the Islamic State of Iraq and the Levant (ISIL) in Iraq.
"The Russian leader expressed support for Baghdad's efforts in the fight against Islamists and bringing about peace and stability in the country," said the Kremlin statement, adding the two leaders also discussed Syria and Iran's nuclear programme.
Earlier this month, Obama and Putin held informal talks on the sidelines of a ceremony to mark the 70th anniversary of the D-Day landings in France.