"These new sanctions were introduced without any international legal foundation whatsoever."
Sanctions were also imposed on firms from China, Sudan and Venezuela.
A spokesman for Rosoboronexport said on Russian television that the US measures were "a case of unscrupulous competition," by the US and that the firm worked in line with all international agreements on arms control, Reuters reported.
Under the sanctions, which usually last two years, no US government agency may enter into any agreement with the organisations specified on the US list.
Lavrov said all of Russia's trade and military co-operation with Iran was carried out "in strict accordance with current international legal norms."
"There can be no other explanation here than the rather arrogant extra-territorial implementation of American laws," he said.
The US has previously imposed similar sanctions against several Russian companies, including Rosoboronexport, in 2006.
Western states say Iran is attempting to develop a nuclear bomb, however Tehran says its nuclear programme is solely for peaceful purposes.
Russia has given limited backing to United Nations sanctions against Iran over its nuclear programme, but says there is no evidence Iran is seeking nuclear weapons.