The United States said it was sending reinforcements to the Gulf after what it called increasing harassment by Iran of ships in the region’s waters.
The moves come after Iran seized two oil tankers in Gulf waters, and one of them was heading to the US.
"The Department of Defense will be making a series of moves to bolster our defensive posture in the Arabian Gulf," White House spokesperson John Kirby told a news briefing.
He added that there would be "details on those reinforcements in coming days."
Iran has harassed, attacked, or interfered with the navigational rights of 15 internationally flagged commercial vessels, Kirby said.
The Gulf waters have witnessed tension in the past years. The most recent was on the 3rd of May when Iran seized a Panama-flagged oil tanker in the Strait of Hormuz.
The oil tanker had been traveling from Dubai toward the UAE’s Fujairah port when it was attacked by IRGCN boats, the Navy said.
"The United States will not allow foreign or regional powers to jeopardize freedom of navigation through the Middle East waterways including the Strait of Hormuz," Kirby said.
About a fifth of the world's oil exports pass through the Strait of Hormuz.