The Kremlin, an ally of the Iran-backed Syrian regime, reportedly welcomed with open arms the first ever state visit to Russia by a ruling Saudi monarch who is expected to discuss a multi-billion dollar defense deal and conflicts in the Middle East.

Shiite powerhouse Iran and Sunni-majority Saudi Arabia are regional foes.

Echoing the United States, Saudi Arabia has repeatedly accused Iran of supporting terrorism and destabilizing the Middle East, an assertion that Tehran denies.

Russia has joined Iran in backing dictator Bashar al-Assad in Syria while Saudi Arabia supports the opposition.

Nevertheless, CNBC reports:

Russia is rolling out the red carpet for King Salman of Saudi Arabia this week, with the monarch leading a high-profile and highly significant delegation to Moscow that will see billions of dollars’ worth of joint investment deals.

When King Salman landed in Moscow and traveled to the center of Moscow, he was greeted with numerous billboards lining the road emblazoned with his own image and a message welcoming him to Russia in Arabic and Russian. His visit is certainly historic, marking the first ever state visit to Russia by a reigning Saudi monarch.

While U.S. President Donald Trump’s administration wants to form an anti-Iran alliance in the Middle East, his Russian counterpart has deployed troops to join Iran-allied Shiite forces in Syria.

However, it appears that both leaders want to cultivate a good relationship with the Sunni kingdom.

Saudi King Salman is expected to meet with Russian President Vladimir Putin on Thursday.

“The leaders will consider joint steps to further develop bilateral cooperation in the trade, economic, investment and cultural-humanitarian areas,” revealed the Kremlin, according to CNBC, which noted that “in addition, international issues including conflicts in the Middle East are expected to form part of the discussions between Putin and the Saudi ruler.”

“Russian-Saudi contacts are important, and their potential is rather great,” Dmitry Peskov, a spokesman for the Kremlin, told reporters, according to the Agence France-Presse (AFP) news agency. ”The political will of Moscow and Riyadh for deeper cooperation on the widest range of issues is clear.”

Citing an anonymous source within the Russian government, CNBC notes that the two leaders are scheduled to hold a series of meetings followed by a state dinner on Thursday.

The source estimated that size of the Saudi delegation to Russia to be more than 100 people, adding that the visit will last four days.

Meanwhile, AFP provides a much higher estimate for the number of Saudis accompanying their king, noting:

King Salman arrived with a delegation of more than 1,000 people, reported Kommersant business daily. Kommersant also said Putin and Salman are due to discuss an arms deal worth more than $3 billion (2.5 billion euros) to supply Riyadh with S-400 air defense systems.

Russian energy minister Alexander Novak told TASS news agency on Wednesday that Saudi Arabia is investing $1 billion into energy projects in Russia though he did not elaborate or specify whether these deals would be signed during the visit.

Russia and Saudi Arabia are on opposite sides of the war in Syria, but both countries are partners in the oil market.

“Salman and Putin are expected to discuss major defense and energy contracts, as well as extending oil production cuts ahead of the OPEC [Organization of Petroleum Exporting Countries] oil cartel meeting in November,” notes AFP.

Saudi Arabia is the most prominent oil-producing member of OPEC, making it the organization’s de facto leader. Russia is not a member.

“The visit is just the latest sign of increasingly cordial relations and closer economic and political ties between the two oil giants,” reports CNBC.

Russia, Iran, and Saudi Arabia are on different sides of the Iraqi Kurdistan independence crisis.

While Russia has said Kurds have the “right” to declare independence, Iran has joined Saudi Arabia, Iraq, Turkey, and Syria in opposing Kurdistan’s efforts to become a sovereign nation.

The United State also objects to an independent Kurdish state in Iraq.