Ukraine crisis: Nato boosts Baltic air power
2 April 2014 Last updated at 16:00 BST
The US Air Force has sent 10 F-15 jets to help Nato boost its military presence in the Baltic states in response to the Russian annexation of Crimea.
Nato Secretary General Anders Fogh Rasmussen has warned that the thousands of troops that Russia has stationed on the border with Ukraine is a threat to European security.
Jonathan Beale reports.