A Russian warship carrying a small contingent of troops is en route to the country's naval base in Tartus to provide security for the installation, U.S. officials told NBC News on Friday.
In March, Moscow reportedly sent elite units of Russian marines and special-operations forces to Syria to conduct anti-terrorism missions in the country.
Two months later, a Russian guided-missile destroyer, named the Smetlivy, was sent to Tartus, joining three other warships deployed to the Russian naval base in Syria on March 19, according to reports at the time by Agence France Presse and al Arabiya.
News of the recent deployment comes amid claims by the White House that U.S. relations with Russia have improved significantly in recent weeks.
However, Deputy National Security Adviser for Strategic Communications Ben Rhodes admitted differences remain between Russia and the United States on removing Syrian President Bashar al-Assad from power.
Rhodes's comments come days before President Obama is scheduled to meet with Russian President Vladimir Putin during the Group of 20 meeting in Mexico next week.
Russia has been an outspoken critic of U.S. and international efforts to depose Assad, as Syria remains one of Moscow's most important allies in the region.
But Assad's brutal armed crackdown on anti-government rebels in Syria has turned up international pressure on Russia and its ties to the regime.
Congress has ratcheted up that pressure in the past days, condemning sales of Russian weapons and helicopters to Assad's forces, who have been using those weapons to slaughter Syrian civilians.
On Friday, a bipartisan group of seven senators led by Sens. John CornynJohn CornynSenators huddle on Russia sanctions as tensions escalate Momentum builds for new COVID-19 relief for businesses Senate panel advances bill blocking tech giants from favoring own products MORE (R-Texas) and Dick DurbinDick DurbinBipartisan Senate group discusses changes to election law Democrats ask for information on specialized Border Patrol teams Democrats face scaled-back agenda after setbacks MORE (D-Ill.) introduced a resolution slamming Russia's continued armed support for the Assad's government via state-sponsored defense firms.
Secretary of State Hillary ClintonHillary Diane Rodham ClintonThe Armageddon elections to come Poll: Trump leads 2024 Republican field with DeSantis in distant second The politics of 'mind control' MORE said earlier this week that Russia is sending attack helicopters to Syria, but the State Department walked back the remarks, saying that the helicopters were refurbished and were being returned to Syria.
Still, a State Department spokeswoman said there is concern that the helicopters will be used by Assad's government to kill civilians and attack opposition forces.
To that end, Cornyn announced Wednesday he was blocking the confirmation of the Army’s new acquisition chief over the Pentagon’s ties to Rosoboronexport, a Russian defense firm that also supplies weapons and support to Syria and Iran.