LONDON: Iran’s offer to host a maritime event in October has been rejected after a proposal led by the US to rescind the bid was approved in a vote at the UN shipping agency’s Council, an agency spokesperson said on Thursday.

The move is likely to further raise tensions between Washington and Iran after Tehran tried to seize the Richmond Voyager tanker, which was 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 UN’s International Maritime Organization (IMO), which was accepted in 2015 by the IMO’s executive Council.

The US, in a working paper seen by Reuters and submitted to the IMO’s Council which is meeting this week, 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 with no 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.

A majority of the IMO Council’s member countries voted in favor of the proposal on Thursday, the IMO spokesperson said, which meant Iran’s offer was rescinded. Forty countries make up the Council.

Iranian officials did not immediately respond to requests for comment.

US State Department spokesperson Matt Miller told reporters in a news briefing: “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.”

The US Navy said in July it had intervened to prevent Iran from seizing two commercial tankers including the Richmond Voyager in the Gulf of Oman, in the latest in a series of attacks on ships in the area since 2019.

In April, the US confiscated an Iranian oil cargo on a tanker at sea in a sanctions enforcement operation, three sources told Reuters. The tanker was anchored outside the US port of Houston, according to ship tracking data on Thursday.

Iran would retaliate against any oil company unloading Iranian oil from the tanker, the Revolutionary Guards navy said on Thursday, according to state media.