This grab taken from a video released by Iran's Army office on April 28, 2023, shows Iranian naval soldiers boarding the Advantage Sweet oil tanker off the coast of Oman. Image Credit: AFP

WASHINGTON: The United States has seen repeated threats from Iran to commercial shipping in the Gulf and the Pentagon will begin to bolster defensive posture in the region, White House spokesman John Kirby said on Friday.

“Today, the Department of Defence will be making a series of moves to bolster our defensive posture in the Arabian Gulf,” Kirby told reporters in a briefing.

The United States has seen repeated Iranian threats and attacks against commercial shippers who are exercising their navigational rights in international waters, Kirby said.

Iran seized a second oil tanker in a week early this month in Gulf waters, and the US State Department called for its release, in the latest escalation in a series of seizures or attacks on commercial vessels in Gulf waters since 2019.

The Bahrain-based Fifth Fleet of the US Navy said on May 3 the Panama-flagged oil tanker Niovi was seized by Iran’s Islamic Revolutionary Guard Corps Navy (IRGCN) while passing through the Strait of Hormuz.

“The United States strongly condemns actions that threaten and interfere with commercial shipping in the Middle East,” Kirby said.

Washington will not allow foreign powers to jeopardize navigating the Middle East waterways including the Strait of Hormuz, Kirby added.

He said US Central Command will provide additional details on those reinforcements in coming days.