UK Prime Minister Keir Starmer arrives at the Joint Expeditionary Force (JEF) summit of northern European state leaders in the Norwegian capital Oslo and says discussions over defence cooperation taking place there are "hugely important". Ukraine and Arctic security are set to be discussed at the summit, a forum which comprises 10 countries -- Denmark, Estonia, Finland, Iceland, Latvia, Lithuania, the Netherlands, Norway, Sweden and the UK -- and was set up to rapidly respond to crises. SOUNDBITE