US National Security Adviser John Bolton considers the talks with Russian officials that took place on October 22-23 during his visit to Moscow "productive", the US official wrote on Twitter.

"Mon. & Tues. I had productive meetings in Moscow w/ Pres Putin & his national security team. We discussed arms control, counterterrorism, Syria, & election meddling," Bolton wrote.

US special services accused Russia of meddling in US 2016 election process. US Special Counsel Robert Mueller is heading the investigation of alleged attempts of meddling, bringing charges against several Russian citizens, as well as against five Americans and one Dutch national.

US President Donald Trump and key members of his team have been repeatedly rejecting all the accusations concerning collusion between the Trump campaign and Russia. Moscow has also been refuting these allegations.