Updated

The top U.S. commander for NATO says Russian forces have used a recent lull in fighting in Ukraine to reposition for what American military officers believe will be another offensive.

Gen. Philip Breedlove tells the Senate Armed Services Committee the United States has been taken by surprise by some of Russia's moves in Ukraine and needs to bolster U.S. intelligence capabilities to better understand President Vladimir Putin's intent in the region.

Breedlove, commander of the U.S. European Command, says the situation in Ukraine is fragile and volatile.

He urged Congress to improve intelligence capabilities focused on Russia.

Breedlove says at a hearing Thursday that Russia's military operations in Ukraine during the past year have underscored critical gaps in U.S. collection and analysis of intelligence.