Coalition forces fire 120mm illumination rounds using an XM905 Advanced Mortar Protection System from a fire base in the al-Shadaddi region of Syria on Feb. 14, 2023. (Nicholas J. De La Pena/U.S. Army)

WASHINGTON — The U.S. military in Syria began to see a significant spike in provocative behavior by Russian aircraft in the two weeks before a Russian jet forced down a U.S. drone over the Black Sea, according to the top general for U.S. Central Command.

Army Gen. Michael Kurilla told senators on Thursday that the Russian air force’s “unprofessional and unsafe” conduct in Syria is not new but has grown in frequency since March 1.

“They fly over our bases with ground attack aircraft with weapons on them in an attempt to try to be provocative,” he said. “They want to try and renegotiate the deconfliction protocols that they violate every day.”

Kurilla’s comments follow similar remarks by Army Gen. Mark Milley, chairman of the Joint Chiefs of Staff, who told reporters Wednesday that Russian military behavior is becoming more aggressive. Russian jets on Tuesday harassed and collided with a U.S. reconnaissance drone, forcing it to crash into the Black Sea.

The Russian Ministry of Defense has denied wrongdoing but said U.S. drone flights off the coast of Crimea, a Ukrainian peninsula that Russia illegally annexed in 2014 and now uses as a major military base for its war on Ukraine, were “provocative in nature.”

Video of the incident released by the Pentagon on Thursday showed a Russian jet dumping fuel on the U.S. drone before clipping the drone’s propeller.

Kurilla told senators that Russian pilots in Syria also routinely exhibit reckless behavior that is “not what we expect” from a professional air force.

He said Russia’s presence in Syria, where the Kremlin intervened in 2015 to prop up the Syrian government amid a civil war, has remained about the same since Russia launched a full-scale invasion of Ukraine last year.

“Syria is very important to Russia, they have taken very little out,” Kurilla said. “They’ve taken a small number of forces, some munitions but generally they’ve stayed about the same.”

Kurilla said Russia is looking to expand its influence in Syria and is seeking a permanent base in the country to strengthen its grip on former Soviet Union states in nearby central Asia. He pointed out CENTCOM, which is responsible for military operations throughout the Middle East and central Asia, has a border with Russia that is six and a half times larger than Russia’s border with NATO countries.

U.S. troops deployed to northeastern Syria in 2014 to support opposition forces and counter the Islamic State terrorist group. More than 900 service members are still stationed in the country to help keep a potential resurgence of the militant group at bay.

The U.S. and Russia set up communication channels in 2015 to prevent any clashes between each other in Syria.