The Palmyra citadel is seen as a Russian vehicle blocks a road leading to the ancient city in Syria on April 14. (Hassan Ammar/AP)

Despite pledging to withdraw the majority of its forces from Syria in March, the Russian military remains firmly entrenched throughout the country and is even continuing to expand in some areas, the Pentagon said Wednesday.

Army Col. Steve Warren, a spokesman for the U.S.-led campaign against the Islamic State, told reporters Tuesday that Russian capabilities are “almost identical” to what they were before President Vladimir Putin’s announcement that his country’s forces would soon be returning home.

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“They continue to have air power there, they continue to have ground forces, they continue to have artillery, said Warren, speaking from Baghdad in a teleconference with reporters. “They still have Spetsnaz providing advice and assistance to the Syrian regime.” Spetsnaz are Russian Special Operations forces.

He added that the Pentagon was also monitoring Russia’s build-up of a forward operating base near the ancient city of Palmyra. The outpost was established in the weeks after Syrian government and Iranian troops, backed by Russian airstrikes and Special Operations forces, routed the Islamic State from Palmyra in March. According to Russian officials, the base was built to support demining operations around the city.

Recent footage of the base, posted online earlier this month by Syria’s al-Masdar news, shows the hallmarks of a small-scale operation, congruent with demining operations. But the footage also includes images of what appears to be a Russian Pantsir S-1, a medium range surface-to-air missile system.

Warren said that the new base gives the Russians “a foothold for a more enduring presence” in the region and that the facility continues to be expanded.

Last week, the American Schools of Oriental Research’s Cultural Heritage Initiative posted satellite imagery demonstrating that the base had been built within the confines of a protected UNESCO heritage site.

“The militarization of vulnerable archaeological areas can cause significant damage to fragile heritage assets,” the group wrote on its Facebook page.

It is unclear how much more the Palmyra base will expand and whether Russia will develop the surrounding area to support some of its attack helicopters stationed nearby. Russian helicopter gunships regularly fly from the Tiyas and al-Shayrat air bases located west of Palmyra.

Warren added that in recent weeks Russian airstrikes, which were previously focused on attacking so-called moderate Syrian opposition groups, have been primarily hitting Islamic State targets. Last year, when Russia began military operations in Syria, officials in Moscow said their air campaign was designed to hit “terrorist” targets, but U.S. officials said that in reality it concentrated on helping the Syrian government reverse gains made by opposition groups.