Below, AFP takes a look at the UK's military presence in the region.

- 'Contingency support' -

Starmer told reporters travelling with him on his plane to Canada for G7 talks on Saturday that Britain was "moving assets to the region, including jets... for contingency support".

The jets are Eurofighter Typhoon planes, according to Britain's defence ministry.

Additional refuelling aircraft have also been deployed from UK bases, according to Downing Street.

Royal Air Force fighter planes are already in the region as part of Operation Shader, the codename given to Britain's contribution to the international campaign against the Islamic State group.

RAF Typhoon jets aided Israel in April 2024 when they shot down an unspecified number of drones fired by Iran, as confirmed by the UK's then-prime minister, Rishi Sunak.

Starmer, Sunak's successor, refused to speculate whether the UK would become directly involved this time in the conflict between the arch foes, which entered their fourth day on Monday.

Iran threatened to target American, British and French bases if Western countries intervened to stop Iranian strikes on Israel.

Tehran also urged London, Paris and Berlin to pressure Israel to stop its deadly attacks on Iran.

- Air bases -

The UK Ministry of Defence did not confirm where the fighter jets were heading to but the BBC reported they would be operating from RAF Akrotiri in Cyprus, Britain's largest air force base in the region.

The permanent joint operating base is where RAF jets fly from for Operation Shader.

Transport, air-to-air refuelling and reconnaissance aircraft operate from there and Britain's other base on Cyprus at Dhekelia.

The RAF's operational headquarters in the Middle East is housed at Al Udeid air base in Qatar, a site that is also used by the US Air Force.

Britain's air force also operates from Al Minhad air base in the United Arab Emirates and Al Musannah air base in Oman, according to information provided by the UK parliament.

- Navy and army -

The British Royal Navy's main operations site in the Middle East is the UK Naval Support Facility in Bahrain in the Gulf.

A type-23 frigate is permanently based there, as are four mine-counter vessels and a Royal Fleet Auxiliary vessel, according to research complied by the House of Commons library.

The navy has also operated a logistics base at Duqm port in Oman, by the Arabian Sea, since 2018.

The British Army permanently deploys two infantry battalions to the bases on Cyprus.

Some 2,220 British soldiers were stationed there as of April last year, according to Ministry of Defence (MoD) statistics.

UK troops are also involved in training Iraqi and Kurdish security forces in combatting IS.

Two hundred personnel were deployed on operations in Iraq as of January 2024, according to the MoD.