Hundreds of NATO troops with heavy equipment are taking part in the Noble Jump military exercises in Poland, the first one that tests the alliance's rapid response readiness in the face of new security challenges on its eastern flank.

The so-called spearhead force was agreed upon at a NATO summit last year in reaction to Russia's role in the separatist fighting in Ukraine that has raised security concerns in other nearby nations.

A deployment exercise began Tuesday near Zielona Gora, in the southwest, to test the Very High Readiness Joint Task Force.

It's part of the Allied Shield exercises held this summer in the region that will involve 14,000 troops from 19 NATO members and three partner nations.