Tehran has denied a US claim that an American warship in the Gulf shot down an Iranian aerial drone, suggesting that perhaps US forces brought down one of their own aircraft instead.

US President Donald Trump said on Thursday that the USS Boxer shot down what he described as an Iranian drone near the Strait of Hormuz after repeated warnings that it was approaching too close to the US Navy amphibious assault ship.

But Iranian officials Friday derided the claim that the US had brought down one of its drones as “delusional,” and insisted that all of its “reconnaissance” drones had safely returned to base.

“Contrary to the delusional claim made by the president of the American regime, all UAVs belonging to the Islamic Republic of Iran in the Persian Gulf region and the Strait of Hormuz, including the one mentioned by the US president, have safely returned to their bases,” Brig-Gen Abolfazl Shekarchi was quoted as saying by state media. “There have been no reports of any confrontation with the USS Boxer.”

Abbas Araghchi, Iran’s quick-witted deputy foreign minister, quipped on Twitter: “We have not lost any drone in the Strait of Hormuz nor anywhere else. I am worried that USS Boxer has shot down their own [UAV] by mistake!”

Tensions high as Trump approves new Iran sanctions: In pictures Show all 17 1 /17 Tensions high as Trump approves new Iran sanctions: In pictures Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, their surface-to-air missile is seen as it shoots down a US surveillance drone EPA Tensions high as Trump approves new Iran sanctions: In pictures This photo shows US RQ-4A Global Hawk unmanned surveillance drone. A drone of this model was shot down by Iran on Thursday 21 June AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures An oil tanker is on fire after it was subject to a suspected attacked at the Gulf of Oman on June 13. The US has blamed Iran for the attack Reuters Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, debris from the downed US drone is seen after it was recovered from Iranian waters AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures US President Trump holds up a signed executive order to increase sanctions on Iran on 24 June AP Tensions high as Trump approves new Iran sanctions: In pictures Iranian President Rouhani stated in a televised address that the White House is "afflicted by mental retardation" following the increase in sanctions on 25 June EPA Tensions high as Trump approves new Iran sanctions: In pictures An Iranian navy boat tackles the fire on the Norwegian owned Front Altair oil tanker after it was hit in a suspected attack AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Iran claims that in this picture released by Iran state TV, debris from the downed US drone is seen after it was recovered from Iranian waters AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures A screenshot from a video released by the US Department of Defense that the US claims to show Iranian removing an unexploded limpet mine form the hull of the Japan-owned ship that was attacked in the Gulf of Oman on June 13 Getty Tensions high as Trump approves new Iran sanctions: In pictures An item reportedly found on the Japan-owned oil tanker that was attacked on June 13 in the Gulf of Oman AFP/Getty Tensions high as Trump approves new Iran sanctions: In pictures A handout photograph from the US Department of Defense shows a composite material that the US claim was left behind on the hull of the Japan-owned oil tanker following the removal of an unexploded limpet mine Getty Tensions high as Trump approves new Iran sanctions: In pictures A view from the cabin of an Iranian navy boat as it tackles the fire on the Norwegian owned Front Altair oil tanker after it was hit in a suspected attack EPA Tensions high as Trump approves new Iran sanctions: In pictures Release by US government A picture released by U.S. Central Command shows damage to the hull of the oil tanker Kokuka Courageous. The picture suggests that the ship is 'likely' to have been hit by a mine as the US Secretary of State Mike Pompeo moves to blame Iran for the suspected attack Reuters Tensions high as Trump approves new Iran sanctions: In pictures Smoke billows from an oil tanker after it was subject to a suspected attacked at the Gulf of Oman on June 13 Reuters Tensions high as Trump approves new Iran sanctions: In pictures Release by US government A picture released by U.S. Central Command shows damage to the hull of the oil tanker Kokuka Courageous. The pictures suggests that the ship is 'likely' to have been hit by a mine as the US Secretary of State Mike Pompeo moves to blame Iran for the suspected attack EPA

The incident and ensuing confusion is the latest flare-up between Iran and the United States in a period of marked escalation following Washington’s move last year to withdraw from the 2015 nuclear deal and begin punishing international companies for doing business with Tehran.

Iran has responded by challenging the US and its allies. It downed an expensive US drone near or in its territory last month and is allegedly behind a number of attempts to sabotage or harass oil tankers moving in and out of the Gulf and the narrow Strait of Hormuz that connects it to the seas.

“These attacks serve Iran’s purpose by offering Tehran the benefit of ambiguity, and they have not resulted in any loss of life to date — thereby increasing the potential to further threaten Gulf shipping without necessarily provoking a major US military response,” the Soufan Center, a consultancy, wrote in a note on Friday.

Details of the latest confrontation remain murky. The US has yet to release surveillance video or other footage showing its targeting of the drone. Iran may be denying its drone was shot to down to avoid having to respond and further escalate, but has said it will soon release footage showing the “ridiculousness of the operation the Americans claim”.

Mr Trump, reading from what was apparently a carefully worded prepared statement, said on Thursday that the Iranian drone “ignored multiple calls to stand down,” describing the incident as “the latest of many provocative and hostile actions against vessels operating in international waters.”

But Brig Gen Shekarji described the US accusations, which were echoed by the Pentagon as well as the White House, as “aimed at provocation and destabilisation of the Persian Gulf region and the strategic Strait of Hormuz.”

The incident and the ones preceding it have spooked the shipping industry. An industry source told The Independent that insurance costs for shippers moving in and out of the Persian Gulf had tripled and quadrupled over the last few weeks as tensions between Iran and the US have spiked, an increase in expenses which will likely be passed on to consumers across the world.

“Until the situation is stabilised the increased threat levels may result in delays, an increase in shipping costs, and included in that is higher insurance premiums, and potential higher energy prices,” said the source. “All of that will be absorbed by consumers.”

At a briefing on Friday, Russian deputy foreign minister Sergei Ryabkov placed blame on Washington and its campaign of “maximum pressure” on Iran for the rising tensions and occasional flare-ups.

“The concentration of forces and equipment in the area of the Persian Gulf, belonging to different countries, is so high that any incidents are possible,” he said, according to the Tass news agency.