By Alistair Bunkall, Defence Correspondent
Britain is to build a new military base in Bahrain in a landmark deal which will enable the UK send more and larger warships to bolster security in the Gulf, amid the growing threat from Islamic State.
The move signals a marked expansion of the Royal Navy presence in the region.
The UK already has four minehunters permanently based at the Mina Salman Port, but the plans will see the existing facilities improved and extended.
These will provide a forward operating base, with a place to plan, store equipment for naval operations, and accommodate personnel.
While the deal is understood to have been in the pipeline for around two years, the rapid gains made by the IS extremist group and resulting instability, underlines its strategic importance.
Foreign Secretary Philip Hammond signed the agreement with Bahrain's foreign minister Sheikh Khalid bin Ahmed bin Mohammed al Khalifa.
Mr Hammond said: "This will guarantee the presence of the Royal Navy in Bahrain well into the future.
"The expansion of Britain's footprint builds upon our 30-year track record of Gulf patrols and is just one example of our growing partnership with Gulf partners to tackle shared strategic and regional threats."
Defence Secretary Michael Fallon said: "This new base is a permanent expansion of the Royal Navy's footprint and will enable Britain to send more and larger ships to reinforce stability in the Gulf.
"We will now be based again in the Gulf for the long term."
The move reaffirms the UK's strategic alliance with Bahrain, despite concerns over security in the Gulf Kingdom.
The Foreign Office's own travel advice warns of the potential for violent protests and demonstrations and advises travellers in the region to be "especially vigilant" to terrorist attacks.
Despite this, the agreement will result in more British service personnel based in the country.
The US 5th Fleet is also based in Bahrain. From there, it allows American and British warships to patrol and carry out exercises in the strategically important Strait of Hormuz, Suez Canal and Strait of Bab al Mandeb at the southern tip of Yemen.
Sheikh Khalid said: "It reaffirms our joint determination to maintain regional security and stability in the face of challenging circumstances, and gives further strength to our multifaceted partnership.
"Bahrain looks forward to the early implementation of today's arrangement and to continuing to work with the UK and other partners to address threats to regional security."
