Russia’s Deputy Foreign Minister Mikahil Bogdanov told state media on Thursday that Moscow had made “direct contact” with Hayat Tahrir al-Sham (HTS), the al-Qaeda offshoot that toppled Syrian dictator Bashar Assad last weekend.

The Russians are keen to persuade Syria’s new rulers to let them keep their air and naval bases.

Bogdanov said talks with HTS are “proceeding in constructive fashion,” particularly on the subject of combating a potentially resurgent Islamic State. He said HTS saw the wisdom of allowing Russia to keep its bases in Syria so it could help with suppressing ISIS.

“The bases are still there, where they were on Syrian territory. No other decisions have been made for the moment,” Bogdanov told Russian state media reporters.

“They were there at the Syrians’ request with the aim of fighting terrorists from the Islamic State. I am proceeding on the basis of the notion that everyone agrees that the fight against terrorism, and what remains of ISIS, is not over,” he said.

Bogdanov, who acts as Russian President Vladimir Putin’s special envoy to the Middle East and Africa, said officials from the Russian embassy have been meeting with HTS representatives at a hotel in Damascus. He said the top priority of those meetings was “ensuring our diplomatic mission’s security and that of the Russian citizens who are on Syrian soil today.”

“Essentially, this interaction is constructive, we are hoping for all promises by representatives of these groups, people, forces responsible for the situation in the city to be fulfilled,” he said.

A source in the Russian Defense Ministry told Bloomberg News on Friday that Moscow “believes it has an informal understanding” with the rebels to retain control of Russian bases, but “the situation could still change amid the instability in Syria.”

“Western officials with knowledge of the interactions said the international community has expressed an informal interest in maintaining the status quo when it came to the Russian bases for the time being, as they could act as a deterrent for any recurrence of extremism in the country,” Bloomberg added.

Russia has two vital bases that appeared to be under threat after the fall of Assad: the naval base at Tartus, which gives Russia access to the Mediterranean Sea, and the airfield at Khmeimim, which has supported Russian military operations in Africa in addition to its military efforts in support of the Assad regime in Syria.

Given that Russia’s support was crucial to keeping Assad in power during the Syrian civil war that began in 2011, Moscow had reason to fear the Assad-hating jihadi rebels would not look kindly upon those Russian bases. Russia also helped Assad to evacuate after his forces crumbled before the lightning-fast insurgent assault, and has given him refuge in Moscow.

Satellite photography suggested most of Russia’s ships and planes abandoned both bases after Damascus fell to the rebels on Sunday.