MOSCOW — Amid growing numbers of reports that Russian forces are taking part in Syria’s ongoing civil war, the United States has sanctioned Russian arms export agency Rosoboronexport and four defense firms for alleged technology control violations, preventing any US department or agency from entering into contracts or agreements with those firms.

The sanctions came as part of a broader move against 23 defense industry entities across the world that had allegedly violated the Iran, North Korea and Syria Nonproliferation Act (INKSNA).

"These entities were sanctioned based on credible information that they have been involved in the transfer or purchase to or from Iran, North Korea or Syria of goods, services or technology listed on multilateral export control lists, US national control lists, or other items that could make a material contribution to the development of weapons of mass destruction or missile proliferation," said US Embassy Moscow spokesman Will Stevens.

Siemon Wezeman, a senior researcher at the Stockholm International Peace Research Institute, told Defense News that "the main result [of the sanctions] will be that US agencies cannot work with the sanctioned firms," unless specific exemptions are made.

"I can imagine that an exemption would be made to buy spare parts for Mi-17 helicopters that the US recently bought for the Afghan Army," Wezeman said. Rosoboronexport completed the contract last year.

Rosoboronexport is the doorway between Russia’s defense industry and foreign export customers. The agency claimed to have delivered $13.2 billion in military exports last year, and at the recent MAKS airshow last week said Russia’s export backlog amounts to $40 billion.

Rosoboronexport said it was unable to comment on the new sanctions at this time.

The famous MiG aircraft company was among those Russian companies singled out in the latest sanctions action, which closely coincided with the Department of Commerce announcing a new round of economic sanctions in response to the ongoing conflict in Ukraine.

The other three companies on the list were high-precision weapons maker Instrument Design Bureau (KBP) Tula; a rocket and missile design bureau near Moscow known as NPO Mishinostroyenia — the same bureau that designed the USSR's SS-19 ICBM; and the Katod company in Novosibirsk, which makes night vision optics, among other things.

Though it was not made clear what set off the latest US sanctions against Russia's defense industry, analysts speculated the move was tied to Russian arms deliveries to Syria and the potential for future sales to Iran.

"Some of the companies enumerated on the [latest] US sanctions list have extensive contracts and contacts with Syria," said Ruslan Pukhov, director of the Moscow-based Center for the Analysis of Strategies and Technologies, a leading defense think tank here.

But the move is also a sign of Washington's displeasure with Moscow's actions over the past few years, including the annexation of Crimea and support for the Syrian government in that nation's ongoing civil war, Pukhov said.

However, Siemon Wezeman of the Stockholm International Peace Research Institute argued that the new sanctions were not particularly aimed at Russia, but rather part of a larger US effort to pressure Iran, Syria and North Korea. 

"I doubt that the Russian companies listed were involved in violations of [the Missile Technology Control Regime] or of any other regimes. Russia is a member [of these regimes] and generally will follow the agreed rules, and if there were some violations, one would expect those to be discussed first in the regimes," Wezeman said.

Both analysts agreed that the move will have little impact on the entities on the list, since Russia's defense industry has already faced sanctions over the Ukraine crisis, and Rosoboronexport has found itself sanctioned by the US in the past, most recently in 2006.

Pukhov said it's likely these firms already have mechanisms in place to mitigate the impact of US sanctions, but that there will be an indirect impact since many contracts are paid in US dollars.

"Some banks, both here and abroad, don't feel comfortable working with entities under US sanctions," Pukhov said, adding that it might discourage non-sanctioned companies from working with Iran or Syria in the future.

Even then, Russian companies are increasingly looking east for customers amid an uncertain business environment as Russia and the West continue to trade shots in the ongoing tit-for-tat sanctions war.

"Rosoboronexport's portfolio of $40 billion predominantly consists of orders from the Asian, Middle Eastern and Latin American countries, which makes it pretty immune to this kind of US move," said Alexey Khlebnikov, an independent Russian geopolitical analyst.

Twitter: @mattb0401