JEDDAH: The US has deployed two warships and more than 3,000 sailors and Marines to the Red Sea in a ramped-up response from Washington to the threat to commercial shipping by Iran.

The Pentagon says Iran has either seized or attempted to take control of nearly 20 internationally flagged ships in the region over the past two years.

The new US forces arrived on board USS Bataan and USS Carter Hall, providing “greater flexibility and maritime capability,” the US Fifth Fleet in Bahrain said on Monday. The deployment adds to efforts “to deter destabilizing activity and de-escalate regional tensions caused by Iran’s harassment and seizures of merchant vessels,” spokesman Cdr. Tim Hawkins said.

Bataan is an amphibious assault ship that can carry fixed-wing aircraft, helicopters and landing craft. The Carter Hall, a dock landing ship, transports Marines and their equipment, and lands them ashore.

The latest deployment came after US forces blocked two attempts by Iran to seize commercial tankers in international waters off Oman on July 5. Tehran said one of the tankers, the Bahamian-flagged Richmond Voyager, had collided with an Iranian vessel and injured five crew.

In April and early May, Iran seized two oil tankers within a week in regional waters. Those incidents came after Israel and the US blamed Iran for a drone strike off the coast of Oman in November on a tanker operated by an Israeli-owned company.

The US said last month it would deploy a destroyer, F-35 and F-16 warplanes, and a marine expeditionary unit to the Middle East to deter Iran from seizing ships in the Gulf. Washington is also preparing to put Marines and navy personnel aboard commercial tankers in the Gulf.

Iran’s foreign ministry spokesman Nasser Kanani said US deployments served only Washington’s interests.“The US government’s military presence in the region has never created security. Their interests in this region have always compelled them to fuel instability and insecurity,” he said. Countries in the Gulf were capable of ensuring their own security,” he said.

Torbjorn Soltvedt of the risk intelligence company Verisk Maplecroft said: “Security will remain a friction point in US-Gulf relations even if the threat posed by Iranian attacks against shipping eases in the short term.

“The perception that the US isn’t doing enough to deter Iranian attacks against international shipping will persist. The need for a new approach is evident.”