Russia sharply has criticized new U.S. sanctions against Iran, saying the measures could harm Moscow's ties with Washington if Russian companies are affected.
The United States on August 11 introduced measures to punish banks, insurance companies, and shippers that help Iran sell its oil, building on oil-trade sanctions against Iran over its nuclear program, which Western powers fear is aimed at achieving nuclear weapons capability.
In a statement, the Russian Foreign Ministry called the measures "overt blackmail" and a "crude contradiction of international law."
It also said that the "constant increase of pressure on Tehran" undermines unity among the six nations leading efforts to resolve the standoff over Iran's nuclear program -- Russia, the United States, China, Britain, France, and Germany -- and hurts the chances of success.
Based on reporting by Reuters and Interfax