Iran would block the Strait of Hormuz in response to possible security threats from the United States, Iranian Ambassador to Russia Seyyed Mahmoud Reza Sajjadi said on Wednesday.
In an interview with Interfax news agency, Sajjadi said Iran would take countermeasures if the US struck the country's nuclear facilities.
"If Iran feels that its security is threatened, it is natural that Iran considers itself entitled to respond and give an appropriate answer. The blockading of the Strait of Hormuz is among the options of this appropriate answer," Sajjadi was quoted as saying.
"We believe that this scenario (the US strike) is possible," he said, adding that Iran has enough power to blockade the strait for "self-defense".
Teheran's ambassador to Moscow said on Wednesday he expected Russia's support to continue because it too was being threatened by the West.
"We expect Russia not to agree to a deal with the West," Sajjadi said.
Russia on Wednesday accused Western powers of trying to "suffocate" the Iranian economy and incite popular discontent with new sanctions such as a proposed oil embargo.
Russian Foreign Minister Sergei Lavrov said all sanctions aimed at winning more transparency from Iran concerning its nuclear program had "exhausted" themselves and new measures threatened to only hurt the Iranian people.
His comments came as EU diplomats closed in on a July date for a full oil embargo that would suit nations such as Italy with a strong reliance on Iranian supplies.
The Republic of Korea warned the US on Tuesday it would have difficulty replacing Iranian crude supplies and expressed concern that sanctions pressure could lead to higher oil prices, according to Reuters.
Indian Foreign Secretary Ranjan Mathai said on Tuesday that his country continues to import oil from Iran.
However, Japan's Finance Minister Jun Azumi reaffirmed on Wednesday that the country intended to further decrease its crude oil imports from Iran but he was also cautious about the impact of sanctions on the oil-rich country.