US Secretary of State John Kerry told his Russian counterpart in a phone call on Wednesday that Russia must withdraw its forces from eastern Ukraine, a senior State Department official said on Thursday, the ABC news reported.

The department didn't provide Lavrov's response. Russia says it has no troops in Ukraine.

Kerry also sought help in ensuring international monitors can access areas under separatist control.

The pair also discussed arms control, Iran, Yemen, Syria and an upcoming meeting of Arctic nations.