Sir Keir Starmer, fresh back from a friendly meeting with Donald Trump in Washington, is due to host the leaders of more than a dozen European countries for a summit in the UK on Sunday to discuss Russia's war in Ukraine and wider European security.
The Baltic states are "very unhappy" after the UK failed to invite their leaders to join a summit on Ukraine this weekend, a European diplomatic source has said.
Wider European security will also be discussed after Mr Trump made clear European NATO allies need to take a much greater responsibility for their own security instead of relying on the powerful US military.
The source said the leaders of Norway, Finland, Sweden and Poland were among the invitees, noting Helsinki and Warsaw have both publicly ruled out contributing troops to an international security force in Ukraine.
They are also, relative to their small size, among the biggest supporters of Ukraine - giving weapons and funding to help the Ukrainian armed forces fight off Russia's invasion - and have been the strongest voices in Europe raising the alarm about the threat posed by Russian President Vladimir Putin for years.
