WASHINGTON -- A top U.S. State Department official says Russia has deployed heavy artillery near the battlefield cities of Homs and Hama, as Moscow deepens its on-the-ground support of the Syrian armed forces' offensive against rebels.
Victoria Nuland, assistant secretary of state for European and Eurasian affairs, also said Moscow's air campaign in Syria was costing between $2 million and $4 million a day, and she described the effort, which has reportedly hit civilian areas, as immoral.
Nuland's comments came on November 4 in testimony before the House Foreign Affairs Committee, where she and another top U.S. diplomat, Anne Patterson, assistant secretary for Near Eastern affairs, faced at-times withering criticism for the U.S. administration's strategy in Syria.
"Now Russia is fielding its own artillery and other ground assets around Hama and Homs, greatly increasing their soldiers' vulnerability to counterattack," she said.
"Russia is hemorrhaging money in this latest adventure," she said.
U.S. security officials and independent experts on November 4 told Reuters that Russia's military force in Syria now included about 4,000 troops.
Moscow has maintained a military presence in Syria for decades as an ally of President Bashar al-Assad's regime, but has declined to comment on the size of its growing force in Syria since it began air strikes on September 30 -- when its force was estimated by Pentagon officials to include about 2,000 troops.
Since then, Russia's air campaign in Syria has included hundreds of attacks by fighter-jet and missile strikes.
While Moscow insists it is hitting Islamic State targets, U.S. officials said on November 4 that up to 90 percent of Russia's targets had, in fact, been moderate Syrian rebel groups -- including some that have been trained and supplied weaponry by the United States.
"Russia's military intervention has dangerously exacerbated an already complex environment," Patterson told the committee.
"Moscow has cynically tried to claim that its strikes are focused on terrorists, but so far, 85 to 90 percent of Syrian strikes have hit the moderate Syrian opposition and they have killed civilians in the process," she said.
"So far, then, this has not been a Russian fight against terrorism so much as an effort to preserve the Assad regime," Patterson said.
Russia's deployment to Syria -- its largest outside the former Soviet Union in two decades -- has included advanced fighter jets, antiaircraft missile systems, tanks, and armored personnel carriers.
But much of the Russian weaponry has been positioned at of the Latakia air base in western Syria.
Analysts say little of that weaponry or Russian personnel have been seen directly on the front lines.
The overwhelming majority of ordnance dropped in Syria has been unguided "dumb" bombs, according to U.S. Defense Secretary Ash Carter and other officials.
Rights activists and other NGO groups have documented an increasing number of civilian targets -- like a marketplace and, allegedly, a mosque -- that have been hit by Russian bombs.
Asked by Representative Bill Keating if she considered the Russian effort "immoral," Patterson agreed.
"It seems quite indiscriminate," she said.
"Assistant Secretary Patterson used that word [immoral] and I don't have a problem with it," Nuland said.
The Kremlin denies it has hit civilians.
A Syrian-government-led offensive, which reportedly includes Iranian forces, began on October 7 in western regions of the country, around the city of Aleppo in the north, though the cities of Hama and Homs, and south to Damascus toward the border with Lebanon.
Analysts and U.S. officials have said the offensive has made only limited advances, and that U.S. TOW antitank missiles being supplied to rebels by Saudi Arabia have played a major factor.
"It's not a slam dunk for the Russians, by any means," Patterson said. "I won't say they've bitten off more than they can chew but they are certainly going to have issues they're going to have to confront, not the least of which is the huge Islamic population inside Russia and on the borders."
Moscow has not announced any casualty figures, with the exception of the death of a serviceman on October 24 who officials said committed suicide.
Meantime, the Obama administration has been gradually increasing the scale of its involvement in Syria, sending ground-support aircraft known as A-10 Warthogs to southeastern Turkey's Incirlik air base and deploying around 50 special-operations troops to northern Syria to work alongside Kurdish forces against Islamic State militants there.
Last week, Pentagon officials said U.S. F-15C air-to-air combat jets would also would be deployed to Incirlik.
That suggests growing concern about possible confrontations between Russian and U.S.-led coalition aircraft.