Moscow accrued power in the Middle East in 2015 by sending troops to Syria, where it and Iran have been key backers of President Bashar al-Assad amid civil war.

The United States, meanwhile, has pulled back while Saudi Arabia has sided with Syrian rebels.

Russia has also strengthened ties with both Sunni Muslim Saudi Arabia and Shi'ite Iran, which are locked in a decades-old contest for influence that veered towards open conflict after a recent spate of attacks on oil assets in the Gulf that Riyadh and Washington blame on Tehran. Iran denies the charges.

Tensions with Iran, which is locked in several proxy wars with Saudi Arabia, have risen to new highs after Washington last year quit a 2015 international nuclear accord with Tehran and re-imposed sanctions.

The Russian president, accompanied by his energy minister and head of Russia's wealth fund, met King Salman at his palace along with de facto ruler Crown Prince Mohammed bin Salman, with whom Putin says he has friendly relations.

Deepening ties have seen non-OPEC Russia, once regarded as a rival in oil markets, join OPEC kingpin Saudi Arabia in forming an alliance known as OPEC+ to support crude prices by restraining output.

At a morning forum convening 300 Saudi and Russian CEOs, Saudi Energy Minister Prince Abdulaziz bin Salman said OPEC+ countries were showing high commitments to the deal, and his Russian counterpart said there were no talks underway to change it.

Asked about concerns Riyadh was cozying up to Moscow, Saudi Minister of State for Foreign Affairs Adel al-Jubeir said he saw no contradiction.

"We don't believe that having close ties with Russia has any negative impact on our relationship with the United States," he said.

Australian Associated Press