In a provocative statement, Tehran announced it had “full supervision over the Persian Gulf” and said the US navy does not belong there.
The Iranian regime has repeatedly threatened to take military action in the Gulf to block other countries’ oil exports.
Experts fear such a move would create major supply disruptions and drive up the price of oil significantly.
Iran is furious at US president Donald Trump for imposing economic sanctions intended to halt its sales of crude.
Washington maintains a fleet in the Gulf that protects oil shipping routes.
General Alireza Tangsiri, of the navy of Iran’s Revolutionary Guards, said: “We can ensure the security of the Persian Gulf.
“There is no need for the presence of aliens like the United States and the countries whose home is not in here.
“All the carriers and military and non-military ships will be controlled and there is full supervision over the Persian Gulf.
“Our presence in the region is physical and constant and night and day.”
Tensions between Tehran and Washington have soared since Mr Trump reimposed sanctions on Iran earlier this month.
In a furious Twitter rant, the White House chief said the measures were the “most biting sanctions ever imposed”.
He added: “Anyone doing business with Iran will not be doing business with the United States. I am asking for world peace, nothing less!”
Senior US officials have said they aim to reduce Iran’s oil exports to zero.
Brian Hook, from the US State Department, said last month: “Our goal is to increase pressure on the Iranian regime by reducing to zero its revenues from crude oil sales.
“We are working to minimise disruptions to the global market, but we are confident that there is sufficient global spare oil production capacity.
“We are prepared to work with countries that are reducing their imports on a case-by-case basis, but as with our other sanctions, we are not looking to grant waivers or licenses.”