Iran has rejected US and British calls to end its support for attacks by Houthi rebels on Israeli-linked vessels in the Red Sea and claimed the accusations were baseless interference as its navy dispatched a destroyer to the vital shipping lane. The Alborz destroyer, operating as a military vessel of the 94th flotilla of the Iranian navy, crossed the Bab-el-Mandeb strait and entered the Red Sea on Monday. It came as Ali Akbar Ahmadian, the secretary of Iran’s supreme national security council (SNSC), met Mohammed Abdulsalam, the Houthi spokesperson, praising the rebel fighters’ “brave actions” against “Zionist aggression”. Tensions between the US and the Iranian-backed Houthis, who are keen to send a message of support to Hamas in Gaza, rose to a new high on Sunday when the US military said its helicopters had sank three Houthi vessels and killed 10 militants after a clash in the middle of the Red Sea, one of the world’s most important trade waterways. The Houthi ships had attacked a commercial ship belonging to the Maersk shipping company, the latest of nearly 20 attacks that have led some shipping companies to abandon the Red Sea route altogether. The UK and the US, possibly alongside another European country, are considering issuing a formal warning to the Houthis that they will strike military installations in Yemen along the Red Sea coast if the rebel fighters do not desist from their attacks on Israeli-linked commercial shipping. The Houthis have said the attacks, which have been disrupting the Red Sea for more than three weeks, will continue until Israel allows full supplies of humanitarian aid into Gaza. The leader of the Yemeni Houthi militia, Abdulmalik al-Houthi, had already warned that his forces would target American battleships in the Red Sea, the Bab al-Mandab strait and the Gulf of Aden in the event of any attack against Yemen by Washington. On Sunday, hours before the high-level meeting between the Iranians and Houthis, David Cameron, the UK foreign secretary, rang his Iranian counterpart, Hossein Amir-Abdollahian, to warn him that Britain held Tehran partly responsible for the attacks. The Iranian foreign ministry spokesperson, Nasser Kanaani, said there was no reason to accuse Iran but added that Tehran stood squarely behind “Palestinian resistance movements”. “Iran proudly announces that it supports Palestinian resistance movements for the liberation of their land,” he said, chastising Cameron’s intervention. Although the Houthis are supported by Iran, their ability to take on the US navy is limited. The militia controls northern Yemen, the strategic port of Hodeidah and the capital Sana’a, but the Saudi-backed and UN-recognised government of Yemen based in the south opposes the attacks on shipping. The US last month launched Operation Prosperity Guardian, a multinational US-led force to protect the sea lanes. Although many western countries contributed a token number of sailors, only the UK has provided ships. Neither Saudi Arabia nor the United Arab Emirates announced they were joining the coalition, reflecting the domestic risks involved in being seen to do anything that supports Israel. Writing in the Daily Telegraph on Monday, the UK defence secretary, Grant Shapps, spelled out the UK’s willingness to take military action to protect freedom of navigation. “We are willing to take direct action, and we won’t hesitate to take further action to deter threats to freedom of navigation in the Red Sea,” he wrote. The Houthis “should be under no misunderstanding: we are committed to holding malign actors accountable for unlawful seizures and attacks”, he added. It is not clear whether the UK government would feel any political requirement to seek the approval of parliament for airstrikes against the Houthis.