The US Central Command (CENTCOM) began confronting Iran's activities in the seas, which Washington considers a threat to the navigation of commercial ships in the Strait of Hormuz and the surrounding waters.
CENTCOM said in a statement that US Secretary of Defense Lloyd Austin ordered the deployment of an Amphibious Readiness Group/Marine Expeditionary Unit into the CENTCOM area of responsibility, in addition to the recently approved forces comprising F-35s, F-16s, and a guided missile destroyer.
The statement added: "US Central Command is committed to defending freedom of navigation within our area of responsibility, which includes some of the most important waterways in the world."
"These additional forces provide unique capabilities, which alongside our partners nations in the region, further safeguard the free flow of international commerce and uphold the rules-based international order, and deter Iranian destabilizing activities in the region," said CENTCOM Commander General Michael Kurilla.
Earlier this month, the US Navy intervened to prevent Iran from seizing two tankers in the Gulf of Oman, including a case in which an Iranian ship fired on an oil tanker.
A US Navy destroyer approached the ships to prevent the oil tanker from being seized, and the Iranian vessel changed course and left the area.
- Iran loses bid to host shipping event
An International Maritime Organization (IMO) spokesman said that its executive body rejected Iran's offer to host a maritime event in October after a proposal led by the US to rescind the bid was approved.
The move will likely raise tensions between Washington and Iran further after Tehran tried to seize the Richmond Voyager tanker, managed by US oil major Chevron, earlier in July in international Gulf waters.
Iran had proposed to host a shipping event in Tehran in late October this year in conjunction with an annual maritime day hosted by the IMO, which was accepted in 2015 by the IMO's Executive Council.
In a working paper seen by Reuters and submitted to the IMO's Council, the US proposed rescinding the decision.
"In the last two years, Iran has attacked, harassed or detained more than 20 vessels engaged in commercial activities," the US said in the paper, which was co-sponsored by Britain.
"Iran has seized or attempted to seize commercial vessels without pretext, warning, or prior justification."
The paper added that Iran had fired on the Richmond Voyager using live fire, "threatening the lives of seafarers onboard," which also prompted the proposal.
- Iran's anger
Most of the IMO Council's 40 member countries voted in favor of the proposal on Thursday, the IMO spokesperson said.
"Iran has no business hosting any official international gathering related to maritime affairs because it has repeatedly demonstrated its contempt for international maritime rules, standards, and safety,” US State Department spokesperson Matt Miller told reporters in a news briefing.
For its part, Iran has expressed outrage, with Iran's foreign ministry criticizing the United States for leading a proposal to cancel its bid.
"This US move proved that the political abuse of the UN's technical and expert institutions has no limits for this country (US), even if it reduces the global credit of those organizations," said Iranian Foreign Ministry spokesman Nasser Kanaani.
- Frequent detentions of ships
Earlier this month, the US Navy said it had intervened to prevent Iran from commandeering two commercial tankers in the Gulf waters.
In April, the US confiscated Iranian oil on a tanker at sea in a sanctions enforcement operation, three sources told Reuters.
According to ship tracking data on Thursday, the tanker was anchored outside the port of Houston.
Iranian Revolutionary Guards Navy commander Alireza Tangsiri said that Tehran would hold Washington responsible for allowing the unloading of the tanker's content without giving further details.
- Iran denies ownership of the oil shipment
In a related development, Iran's oil ministry said the oil cargo of an Iranian-flagged supertanker seized by Indonesia last week does not belong to Tehran, according to state media.
In a statement, the Iranian Oil Ministry did not identify the owner of the cargo of MT Arman 114, an Iranian-flagged supertanker suspected of involvement in the illegal transshipment of crude oil, which Indonesia's coast guard said on July 11 it had seized.
"Published news linking the cargo of this ship to ... Iran have no validity, and this is done to create a negative atmosphere against our country," the oil ministry statement said, without elaborating.
- Tehran Detains a fourth US citizen
Iran arrested a fourth US citizen, which further complicated the efforts of US President Joe Biden's administration to secure an exchange of prisoners and lower tensions with Tehran.
Semafor reported that some sources believe the arrest of the US citizen is now a central part of stepped-up negotiations between the two countries aimed at swapping Iranians detained in Western prisons for US nationals.
The talks, which have taken place in Oman and other countries, also revolve around the US agreeing to green-light the release of billions of dollars of Iran's funds frozen in overseas banks, such as in South Korea.
Iranian officials have publicly hinted for months that a deal with Washington over this exchange is imminent, a position that the Biden administration has disputed.
But people familiar with the case said that now including a fourth US national, whose identity is withheld, could prompt Tehran to up its demands.
