Four US minesweepers have arrived in the Gulf to bolster the US Fifth Fleet and ensure the safety of shipping routes, the US Navy said, as an Iranian military chief suggested on Monday that Iran might try to block the Strait of Hormuz to defend its interests.

The four additional mine countermeasures (MCM) ships arrived on Saturday and are scheduled for a seven-month deployment in an area of operations that includes the Gulf, Gulf of Oman, Red Sea and parts of the Indian Ocean.

The area also includes two other critical shipping choke points of the Suez Canal and the Strait of Bab al Mandab between the southern tip of Yemen and Africa.

"MCM ships conduct operations with coalition forces in order to ensure the continued, safe flow of maritime traffic in international waterways," the US Navy said in a statement late on Sunday.

Tensions between Iran and the West over the Islamic Republic's nuclear programme have raised fears that Iran might try to block Hormuz - a vital shipping route for the global economy - if it is prevented from exporting its own oil by western sanctions that are to tighten again on July 1.

The commander of Iran's ground forces, Ahmad-Reza Pourdastan, was quoted by the Iranian Student News Agency (Isna) on Monday as saying Iran might use its influence over the Strait of Hormuz to defend its interests.

More than a third of all seaborne traded oil was shipped through Hormuz last year, according to the US Energy Information Administration (EIA), and even a brief blockage could cause price spikes that threaten global economic growth.

The USS Sentry, Devastator, Pioneer and Warrior are designed to clear mines from vital waterways, supporting a US Central Command request for more MCM support, the US Navy statement said. – Reuters