Russia was preparing to deliver missiles and other military equipment to the Houthi rebels in Yemen late last month but pulled back at the last minute amid a flurry of behind-the-scenes efforts by the United States and Saudi Arabia to stop it.

The Saudis, who were locked in a brutal war with the Houthis for years before the US helped to negotiate a fragile truce in 2022, warned Russia against arming one of their biggest adversaries upon learning of the plans, the sources said.

The US, which has been involved in several diplomatic efforts to stop the Russians from arming the Iran-backed rebels, separately asked the Saudis to help convince Moscow not to pursue the effort, two of the sources said.

The US-Saudi discussions and the imminent weapons transfer have not been previously reported. The Saudi Embassy in the US declined to comment and the Kremlin did not return a request for comment.

The US designated the Houthis as a global terrorist organization in January, following months of Houthi missile and drone attacks against commercial shipping in the Red Sea that killed several mariners and hobbled global trade. Despite several rounds of sanctions and US military attacks on Houthi weapons infrastructure, however, the rebels have continued to attack commercial ships in the crucial waterway.

A senior US official declined to discuss the specifics of Russia’s plans to arm the Houthis. But the official said that the US regards any attempt by a third party to bolster the Houthis’ weapons supplies “as antithetical to the goals we are pursuing” when it comes to achieving a lasting peace settlement in Yemen between the Houthis and the Saudis, and helping to stabilize the region. For the Houthis to engage in that kind of weapons transaction, moreover, “would demonstrate to us a lack of commitment” by the Houthis to peace talks, the official said.

Currently, the Houthis “appear to be drifting further away from a commitment to a negotiated peace in Yemen,” the official said.

Russian ships in the Red Sea

It remains unclear to the US intelligence community whether Saudi Arabia’s pushback was the key to Russia abandoning its plan to arm the Houthis, or whether it was just one of a number of factors that led Russian President Vladimir Putin to change his mind, the sources said.

The Russians have viewed arming and advising the Houthis as a way to retaliate against the Biden administration for its decision to allow Ukraine to strike inside Russian territory using US-provided weapons, officials said.

And while the imminent weapons transfer was pulled back, Russia did deploy military personnel to Yemen to help advise the Houthis over a three-day period in late July, the sources said.

US officials watched as large Russian ships made an unusual stop in the southern Red Sea, where the Russian personnel disembarked, were picked up by the Houthis in a boat, and ferried to Yemen, the sources said.

The Russians carried bags with them, but nothing that appeared large enough to carry weapons or weapons components, the sources said. It is not clear whether the Russian ships were carrying the equipment that Russia had been preparing to transfer to the Houthis before the Kremlin abandoned the plan.

Before and during the Russians’ visit to Yemen, the Houthis took the unusual step of issuing a notice to mariners, which alerts ships to potential dangers at sea. A US official said intelligence indicated that the Houthis had intended to conduct live fire exercises while hosting the Russians, but those plans appear to have been scrapped, too.

The Houthis began their near-daily attacks on ships transiting the Red Sea in November 2023, prompting the US and UK to conduct several rounds of airstrikes inside Yemen to try to eliminate their weapons infrastructure.

The strikes do not appear to have significantly impacted the Houthis’ stockpiles, and the rebel group even showed signs of being willing to sell some weapons to the Somali militant group al-Shabaab in June, CNN previously reported. But their supply is not infinite, particularly because the US has sanctioned several entities over the last few months — primarily out of China and Oman — believed to be supplying the group with weapons components.

The Houthis are also in particular need of new radar systems, which US Central Command forces have regularly targeted to try to blunt the Houthis’ missile attacks.

There have been indications as well that the Houthis’ primary patron, Iran, has had some concerns about the group’s attack strategy, whereas Russia has been critical of the US and UK attacks on the Houthis.