The conversation was initiated by the US side. Russian Ministry of Defense does not disclose the details of it.
The Pentagon confirmed that Esper and his Russian counterpart were having a phone conversation. However, Washington also declined to provide any information on the topics discussed, Reuters reports.
Relations between the United States and Russia remain tensed on many issues, from Syria to Ukraine. Tensions between the countries are also compounded by allegations of Russia's interference with US policies, which Moscow denies.
The Pentagon has put campaigns against Russia and China at the center of its national defense strategy, after more than a decade and a half of focusing its efforts on fighting Islamist soldiers.
As we reported earlier, President of Russia Vladimir Putin said that he would not mind if the White House made public his talks with President Trump at a summit meeting last year because there was nothing incriminating in their conversations.