The Russian base in Tartus is the country's only naval installation outside the borders of the former Soviet Union. A Russian naval squadron conducted a port visit in January, just as violence between rebel forces and government troops loyal to Syrian strongman Bashar al-Assad was coming to a head.
The port call was interpreted by many regional observers as a show of support by Moscow for the Assad regime.
Last Friday, Deputy Defense Minister Anatoly Antonov dismissed claims that Moscow would send special-operations units to Syria to support Assad's crackdown on rebel forces. “There are no [Russian] special forces with rifles and grenade launchers running around,” he told The Associated Press.
News of the troops' arrival comes a week after a group of lawmakers pressed the Pentagon to cut ties with a Russian weapons maker accused of providing arms to the Syrian government.
Led by Sens. John CornynJohn CornynSenate Dems: Border wall is a budget 'poison pill' Senate braces for fallout over Supreme Court fight Former congressman indicted on conspiracy charges MORE (R-Texas), Dick DurbinDick DurbinRepublicans seek to lower odds of a shutdown No. 2 Senate Democrat opposes Trump's Supreme Court pick The Hill’s Whip List: 32 Dems are against Trump’s Supreme Court nominee MORE (D-Ill.), Kelly AyotteKelly AyotteFEC commissioner to Trump: Prove voter fraud Live coverage: Day three of Supreme Court nominee hearing Lewandowski saw no evidence of voter fraud in New Hampshire MORE (R-N.H.) and Kirsten GillibrandKirsten GillibrandThe Hill’s Whip List: 32 Dems are against Trump’s Supreme Court nominee Senators demand Pentagon action after nude photo scandal Chelsea Clinton to be honored by Variety, Lifetime MORE (D-N.Y.), the bipartisan group of 17 senators urged DOD to end all business with the Russian-based defense firm Rosoboronexport.
The company is currently under contract with the Pentagon to supply 21 Mi-17 helicopters to the Afghan National Security Forces, at a cost of $375 million.
“U.S. taxpayers should not be put in a position where they are indirectly subsidizing the mass murder of Syrian civilians,” the senators wrote in a letter to Defense Secretary Leon Panetta last Monday.
"We urge you to use all available leverage to press Russia and Russian entities to end their support of the Assad regime ... which is within your authority as Secretary of Defense," they added.
Some on Capitol Hill have called for direct action by the United States to support the Syrian rebels. Sens. John McCainJohn McCainOvernight Finance: Senate Dems call for investigation of acting SEC chairman | Wyden: Russia probe should focus on Trump financial ties | Dems seek more money for IRS Overnight Defense: Top general talks Afghanistan, civilian casualties | Defense hawks slam short-term funding McCain and Graham: We won't back short-term government funding bill MORE (R-Ariz.) and Joe Lieberman (I-Conn.) have led the charge to supply anti-government forces with American arms and provide air cover with U.S. warplanes.
However, many rank-and-file Republicans have been hesitant to back McCain's call for support. Senate lawmakers are reluctant to get involved militarily in Syria, fearing the United States could be drawn into another protracted conflict in the Middle East.