"The deployment of U.S. military assets in the Persian Gulf region will continue as it has for decades," said spokesman Commander Bill Speaks in answer to threats, sounded from Iranian army commander Ataollah Salehi about U.S. Navy carrier, who left the Persian Gulf as Iranian Navy war games started.
"The U.S. Navy operates under international maritime conventions to maintain a constant state of high vigilance in order to ensure the continued, safe flow of maritime traffic in waterways critical to global commerce", Reuters reported.
The aircraft carrier USS John C Stennis leads a U.S. Navy task force in the region. It is now outside the Gulf in the Arabian Sea, providing air support for the war in Afghanistan, said Lieutenant Rebecca Rebarich, spokeswoman for the 5th Fleet.
The carrier left the Gulf on December 27 on a planned routine transit through the Strait of Hormuz, she said.
Forty percent of the world's traded oil flows through that narrow straight -- which Iran threatened last month to shut if sanctions halted its oil exports.
Brent crude futures were up more than $4 in late Tuesday afternoon trade in London, pushing above $111 a barrel.
Tehran's latest threat comes at a time when sanctions are having an impact on its economy, and the country faces political uncertainty with an election in March, its first since a 2009 vote that triggered countrywide demonstrations.
The West has imposed the increasingly tight sanctions over Iran's nuclear program, which Tehran says is strictly peaceful but Western countries believe aims to build an atomic bomb.
After years of measures that had little impact, the new sanctions are the first that could have a serious effect on Iran's oil trade, 60 percent of its economy.
Sanctions signed into law by U.S. President Barack Obama on New Year's Eve would cut financial institutions that work with Iran's central bank off from the U.S. financial system, blocking the main path for Iran to receive payments for its crude.