Barack Obama, then US president, ordered the seizure of two Russian diplomatic compounds and the expulsion of 35 Russian diplomats in December over what he said was their involvement in hacking the 2016 US presidential election campaign, something Russia flatly denies.
Russia has said too many American spies operate in Moscow under diplomatic cover and has said it might expel some of them to retaliate over the incident, Reuters reported.
It has said a lot will depend on the outcome of a meeting in Washington later on Monday between Russian Deputy Foreign Minister Sergei Ryabkov and US Undersecretary of State Thomas Shannon.
"We still hope that our American colleagues will demonstrate a certain political wisdom and political will," Kremlin spokesman Dmitry Peskov told a conference call with reporters when asked about the dispute.
Peskov said any US preconditions to return the property would be unacceptable for Moscow and said Washington's failure to hand back the compounds ran counter to international law.
He declined to discuss what steps Russia would take if the meeting between Ryabkov and Shannon failed to resolve the row.