Breedlove, who also heads the US military's Europe Command, yesterday spoke to lawmakers and reporters in Washington to warn of the increase in violence in Ukraine's Donbass region and of Russia's generally aggressive stance.
"In the last week, (there were) over 450 attacks along the line of contact," Breedlove said after speaking to the US ambassador in Ukraine.
"There are several disturbing trends in those attacks, and that is that some of them are now happening in places that were heretofore quiet ... and also that the type and style of the attacks reflect the weapons that were (previously) banned."
The four-star general added that Russia had put "well above" 1,000 pieces of military hardware into Ukraine in the past year including armoured personnel carriers and artillery. Breedlove's remarks came the same day as three Ukrainian soldiers were reported killed and two wounded when their car hit a mine in the former Soviet republic's pro-Russian separatist east.
A military spokesman in Kiev said another three government troops were wounded in separate exchanges of fire near the front separating rebel-run parts of the industrial Lugansk and Donetsk regions from the rest of Ukraine.