Moscow on Thursday called new U.S. sanctions against Russia over the Salisbury poisoning incident "unacceptable".
Kremlin spokesman Dmitry Peskov told reporters that both these sanctions and those imposed before by Washington were "illegal and against the international law".
Peskov's remarks came a day after the U.S. State Department announced the intention to impose new sanctions on Russia over the poisoning of Russian agent Sergei Skripal and his daughter Yulia Skripal in March in the southern English city of Salisbury.
"Of course, such decisions made by the American side are absolutely unfriendly. And it is unlikely that they can be somehow associated with the difficult but constructive atmosphere that was at the last meeting of the two presidents," Peskov said.
However, Russia still hopes for the possibility of restoring constructive relations with the U.S., he said, adding that "it is too early to talk about retaliatory measures".
The sanctions are expected to take effect on or around Aug. 22 following a congressional notification period.
The British government has blamed the incident on Russia, linking the nerve agent to a series of Russia-developed chemical weapons collectively known as Novichok. The Kremlin has denied responsibility.
The Skripals have recovered from the alleged assassination attempt following intensive care at the hospital.