US National Security Adviser Robert O’Brien. Photo: Erik Simander / TT News Agency / via Reuters.

US National Security Adviser Robert O’Brien will travel to Moscow to attend Russia’s World War Two Victory Day celebrations in May, US ambassador John Sullivan was cited as saying on Thursday by the Interfax news agency.

President Vladimir Putin presides over an annual parade on May 9 to commemorate the Soviet Union’s World War Two victory over Nazi Germany and uses the occasion to show off the country’s military hardware.

Relations between Russia and the United States are at post-Cold War lows, strained by everything from Russia’s detention on spying charges of a former US Marine to US allegations that Moscow meddled in its 2016 election.

Russia invited US President Donald Trump to attend the May 9 event, but he declined. US officials said he had wanted to go, but faced pressure from his advisers not to.

The spread of the new coronavirus has raised questions over whether the May 9 parade will go ahead, but the Kremlin has said preparations are going ahead as normal.

A US embassy spokeswoman did not immediately reply to a request to comment.