King Salman of Saudi Arabia will visit Russia on Thursday, senior Kremlin aide Yury Ushakov was quoted by the TASS news agency as saying.
"We are awaiting the king's visit on Thursday," Ushakov said Monday, without elaborating.
The visit comes a month before members of the OPEC oil cartel, of which Saudi Arabia is the biggest producer, are due to meet with the other nations that have joined them in cutting crude output, including Russia, to discuss extending the pact that has helped prop up prices.
OPEC and its allies agreed from the beginning of 2017 to cut their production by around 1.8 million barrels per day for six months. It was subsequently extended through March 2018.