The personnel are taking part in a series of multi-national exercises focussing on European security, the ministry announced on its website.

Personnel from other nations joining the UK-led high-readiness Joint Expeditionary Force (JEF), to partake in the exercise, will bring the total number to around 3,000, the ministry says.

Estonia joins the UK and the other JEF nations, namely Denmark, Finland, Latvia, Lithuania, the Netherlands, Norway and Sweden.

Defence ministers and other representatives from the JEF nations are to meet this week at the UK Ministry of Defence, to discuss preparations for mobilising the JEF and the exercise itself, known as Baltic Protector, the first ever JEF maritime deployment on this scale.

Baltic Protector deployment will include around 20 naval vessels from the participating nations, with maritime tactical exercises, amphibious drills, amphibious raiding practice, shore landings and naval manoeuvres all planned. So far as the UK contingent goes, members from the British Army and the Royal Air Force (RAF) are also to take part, as well as from the Royal Navy.

At full strength, the JEF has the capability to mobilise over 10,000 personnel, it is reported, in support of a variety of missions to deliver rapid and far-reaching effect.

Versatile force

UK Defence Secretary Gavin Williamson (Conservative) noted that: ''As Britain prepares to leave the EU, our unwavering commitment to European security and stability is more important than ever.

''Deploying our world class sailors and marines to the Baltic Sea, alongside our international allies, firmly underlines Britain's leading role in Europe,'' Mr Williamson went on.

Baltic Protector is set to be made up of three major exercises, and is aimed at integrating UK and partner nations, to test their ability to operate together.

JEF personnel and ships are also to work alongside NATO allies during the deployment, the ministry said, which should further underline its versatility and commitment to supporting European security.

Cdre James Parkin, RN, Commander of the JEF Maritime Task Group, said of the deployment that it was a huge privilege to command.

''I am greatly looking forward to working with our close friends and partners from the other eight Joint Expeditionary Force partner nations. Together, this UK-led Maritime Task Group will conduct a series of demanding amphibious exercises and maritime security patrols across the Baltic Sea that will serve to improve the way we operate together and our readiness to respond to crisis,'' Cdre Parkin continued.

The JEF was established at the 2014 NATO Summit and launched a year later, becoming fully operational with the signing of a comprehensive Memorandum of Understanding in June 2018, according to the Ministry of Defence site.

As an adaptable high-readiness force, its competencies include combat operations, deterrence, and humanitarian support, and it can operate independently or in support of multinational organisations, including the UN, and the EU, as well as NATO.