Iran must not give in to U.S. "provocations," Russia said on Wednesday, following months of mounting tension between Washington and Tehran.
"We are urging maximum restraint and caution, not to give in to provocations and aggressive rhetoric," Foreign Ministry spokeswoman Maria Zakharova told reporters.
Tehran and Washington have traded barbs over a spate of incidents in the past year involving their forces in the sensitive waters of the Gulf.
Their latest high-seas confrontation came on April 15, when the United States said 11 Iranian boats harassed its navy ships in what it described as the international waters of the "Arabian Gulf."
U.S. President Donald Trump tweeted that he had ordered the U.S. Navy to "shoot down and destroy any and all Iranian gunboats if they harass our ships at sea."
Iran's president replied on Wednesday that "the Americans should know that this gulf is called the Persian Gulf, not the New York Gulf or the Washington Gulf."
Zakharova stressed that both countries should act in "strict accordance with international norms and regulations."
"Moscow has always considered stability and security in the Gulf to be a key factor that influences the situation in the wider regional context," she added.