"I do not think you will see fracture, division or disunity as a result of this decision," Sullivan said, commenting on Washington's recent decision to send cluster bombs to Ukraine.
He added that Kiev's written assurances to Washington mention that these weapons will not be used on the Russian territory.
"One [example] being that they will not use them on Russian territory, they will only use them on their own territory … Second — that they will not use them in populated areas," Sullivan said.