Delegations, led by Russian President Vladimir Putin (3rd R) and U.S. National Security Adviser John Bolton (3rd L), attend a meeting at the Kremlin in Moscow, Russia October 23, 2018. REUTERS/Maxim Shemetov

MOSCOW (Reuters) - U.S. national security advisor John Bolton said on Tuesday Washington had yet to take a decision on whether to impose new sanctions on Russia.

He said the White House was reviewing whether new sanctions were needed in the light of the nerve agent poisoning in Britain of former Russian spy Sergei Skripal and his daughter. London blames Russia for the poisoning, an allegation that Moscow has denied.