The defence ministers of Estonia, Latvia, Lithuania, the Netherlands, Norway, Denmark, Sweden, Finland and the United Kingdom signed the JEF agreement, the Ministry of Defence said.

"The United Kingdom has become one of Estonia's most important and closest allies, and therefore Estonia joining the Joint Expeditionary Force was a natural sequel to our good long-term cooperation," Minister of Defence Jüri Luik said.

The planning phase of JET has been concluded and signing the cooperation agreement marks the UK-led force created in 2015 becoming fully operational, the Ministry of Defence said.

In addition to operations, the aim of the cooperation framework is carrying out joint exercises. "We wish for the exercises of the Joint Expeditionary Force would be connected to the security challenges of our region," Luik said, adding that an exercise in the Baltic Sea, including in the waters of the Baltic countries, is planned to be carried out already next year.