Nato leaders will today discuss the crisis in Ukraine with the country's president Petro Poroshenko.
The alliance is expected to approve a package of support, setting up trust funds expected to be worth around 12 million euros to improve Ukrainian military capabilities.
Russia's relationship with Nato will also be discussed.
A senior Nato official told Reuters that for now, at least, Russia was not a partner.
The official, who asked to remain anonymous, said: "Russia has basically violated very fundamental agreements on the basis of which we have constructed peace and security in Europe for the last two decades.
"So we have to now figure out what kind of relationship we can have with Russia."
Angus Raffle, 8, says his surprise meeting with the President at Stonehenge was "awesome". His mother says she "squealed like a teenager".
The language has been ramped up at this Nato summit, yet caution appears the order of the day after the mistakes of recent history.
The US President's motorcade pulled up at the school with his black stretch limousine bearing a Welsh flag for the first time in history.