Such a Ukraine, "firmly committed to democracy and the rule of law, is key to Euro-Atlantic security," NATO said in a statement agreed by member state defence ministers.
In line with current agreements with Kiev, "NATO allies will continue to support Ukrainian sovereignty and independence, territorial integrity, democratic development, and the principle of inviolability of frontiers, as key factors of stability and security in Central and Eastern Europe and on the continent as a whole."
Brawls broke out today in Crimea between demonstrators wanting to stick with Kiev and opponents backing closer links with former Cold War master Russia.
Crimea is home to Russia's Black Sea fleet and tensions mounted further after President Vladimir Putin ordered military preparedness checks in western Russia.
The drill -- similar to one last year in the east -- involves army, navy and airforce troops based in the western military district, a vast territory bordering Ukraine, Belarus, the Baltic states, Finland and the Arctic.