Russian forces appear to be expanding their military presence in Syria through the development of two additional bases that pose new challenges for the Obama administration as it struggles to avert a clash with Moscow in the Middle East, Wall Street Journal reported.

Private satellite images released Tuesday revealed new construction at two Syrian military facilities near the Mediterranean coast, the latest sign Russia is preparing to inject its military forces into the country’s 4½-year war.

While US military officials assessed the importance of the projects and overall buildup, the Obama administration is seeking to transform the potential showdown into a fresh diplomatic initiative to push Syrian President Bashar al-Assad—Russia’s longtime ally—from power, senior administration officials said.

Specifically, officials are exploring whether the US could work with Moscow to ease Assad from power and pave the way for a successor from his Alawite sect, preventing a collapse of the government and a likely takeover by Daesh extremists, a senior administration official said Tuesday.

President Barack Obama plans to push the idea during a series of meetings next week during the United Nations General Assembly in New York. “We have to learn more about Russia’s intentions before we know how viable it is,” said one senior administration official.

If Russian President Vladimir Putin wants to flex Russia’s military to protect Assad, relations with Moscow might deteriorate, as they did when Russia seized Ukraine’s Crimean peninsula last year.

But if Russia is instead trying to maintain its existing influence, even if Assad is ousted, the White House sees a potential diplomatic opening.

As part of the resolution, Russia and Iran would get to protect their interests in Syria, and Moscow would contribute to the US-led fight against Daesh militants, the official said.

The Obama administration’s maneuvering is being driven largely by Russia’s moves to build up its military position, which until recently was largely focused on an air base south of the Syrian port city of Latakia.

Moscow has dispatched more than two dozen combat aircraft to the airfield, where Russian surveillance drones have started flying, according to US defense officials. Russia has also sent tanks, air-defense systems, armored-personnel carriers and enough housing for 2,000 people, officials have said.

Now, satellite images provided by IHS Jane’s, a defense-intelligence provider, show what appears to be an additional, previously undisclosed, Russian military expansion.

The images from mid-September show development of a weapons depot and military facility north of Latakia, suggesting that Russia is preparing to place troops in both places.

While Russia’s recent activity in Syria has raised concern within the administration, US officials are trying not to inflame tensions as they try to determine the scope for diplomacy.

Mr. Putin is also attending the UN General Assembly and the White House is still weighing whether Obama meets with him.

The Syrian war has left 250,000 people dead, created a security vacuum filled by Deash militants, and sparked a refugee crisis creating strains across the Middle East and Europe, with more than four million people displaced.

Pentagon officials said they weren’t certain if development of the two bases seen in the satellite images was related to Russia’s military presence at the airfield.

“There is clearly capability beyond just force protection that is on the ground there,” said one senior military official. “But the questions remain: What are they going do with it? Where are they going to do it? Who are they going to do it with? And who are they going to do it against?”

US officials are trying to avoid a complete collapse of the regime infrastructure, which they say would be too destabilizing and create an environment where extremist groups would fill the void as happened after the fall of Saddam Hussein in Iraq.

White House press secretary Josh Earnest said Obama believes “a Russian decision to double down on Assad’s leadership is a losing bet.” Earnest said Russia’s intentions within Syria remain unclear.

“But we continue to be interested in Russia sending a signal about their willingness to constructively support the international coalition to degrade and ultimately destroy” Daesh, he said.