Poland's defense minister has launched a major international military exercise that is to test readiness to react to security threats at a time of armed conflict in neighboring Ukraine.

Tomasz Siemoniak said Wednesday he had originally planned that the biannual exercise would be at command level only, but due to the situation in Ukraine, which also involves Russia, he decided it should have wider participation.

The Anakonda-14 exercise involves 12,500 troops, including some 750 from the U.S., Canada, Britain, the Netherlands, the Czech Republic and Hungary, as well as Lithuania and Estonia, which border Russia.

The scenario for the 10-day exercise calls for the protection of borders and will be held at four test ranges in northern Poland.