Back in December, Russian President Vladimir Putin decided not to respond to sanctions imposed by the outgoing US administration and act in accordance with the ties built with the new US leadership.
"The issue is of course important. We showed extraordinary flexibility and a constructive approach… We reacted as we did, but in diplomatic practice and in all international affairs, the principle of reciprocity has not been canceled… The Russian side has enough patience, but it is not unlimited," Ushakov told reporters.
The aide stressed that Moscow cannot but respond to such actions.
"Any normal country in the world responds to an unfriendly step with some measures that it considers equivalent, but we do not want this," Ushakov said.
The Donald Trump administration is currently considering the return of the two facilities ahead of the US president's first meeting with Russian President Vladimir Putin at the G50 summit in Germany this week.
Russian Foreign Ministry spokeswoman Maria Zakharova said earlier that Washington pledged to prepare proposals in the near future aimed to settle the issue of Russian diplomatic property seized in the United States.