"It goes without saying that the main principle of reacting to sanctions is reciprocity," Kremlin spokesman Dmitry Peskov told a conference call with reporters.
"At our experts' level, naturally, different variants (of Russian) sanctions are now being formulated and proposed," he added, Reuters reported.
Peskov also said the Kremlin was not ruling out a meeting between Russian President Vladimir Putin and US President Donald Trump on the sidelines of a G-20 summit in Germany next month but "nothing concrete has so far been agreed".