The 81-year-old king, who acceded to the throne in 2015, is set for later this week.
“We are awaiting the king´s visit on Thursday,” President Vladimir Putin´s foreign policy aide, Yury Ushakov, was quoted by state TASS news agency as saying on Monday.
The Saudi government, in turn, called the visit between 4 – 7 October “historic”. President Putin has only been to the Saudi capital of Riyadh once, in 2007, which is to date the only official state Russian visit to the country.
The visit comes before next month’s Organisation of the Petroleum Exporting Countries (Opec) summit in Vienna, Austria, of which Riyadh and Moscow are the most powerful members.
Talks are expected to focus on extending the bloc’s January 2017 commitment to cut crude oil output production, which has helped prop up oil prices during a glut in supplies worldwide.
“King Salman does not do courtesy calls so it can be reasonably assumed that his first official visit to the Russian capital is a serious event,” Chris Weafer, a senior partner at consultancy Macro-Advisory, said in a statement.
“It is not too many years ago that such a visit would have been difficult, if not impossible. Today that has changed 180 degrees. Both countries now see political and economic advantages from a closer, albeit pragmatic, relationship.”
While Moscow and Riyadh are economic allies, diplomatic relations have been strained since the Cold War, when Saudi Arabia supported the muhadjadeen resistance against the Soviet Union.
King Salman’s trip, however, highlights Russia’s growing power in the Middle East.
It comes after Russian Foreign Minister Sergey Lavrov visited Saudi Arabia for talks on de-escalation in Syria last month.