More than 1,800 people have died from the mosquito-borne viral illness, up from over 1,000 deaths reported last month in the year through March
"The president urged President Putin to uphold Russia's commitments under the Minsk agreements, underscoring the US and our partners' commitment to Ukraine's sovereignty," the official said on Sunday.
The summit is taking place in Peru's capital, Lima.
Obama also emphasised the need for their two countries' foreign ministers "to continue pursuing initiatives, together with the broader international community, to diminish the violence and alleviate the suffering of the Syrian people," the official said.