Blinken said this at a press conference with British Foreign Minister James Cleverly, reports CNN.
"They have in place ... what they need to continue to be successful in regaining territory that was seized by force by Russia over the last 14 months," Blinken said.
The US Secretary of State noted that it is not only about weapons, but also about military skills and operational planning.
"It's not only the weapons; it's the training. It's making sure that the Ukrainians can maintain the systems that we provide them, and it's important, of course, that they have the right plans, again, to be successful," Blinken said.
Earlier, Blinken called Ukraine's successful counteroffensive the fastest way to move to negotiations.
On May 9, the United States announced a new $1.2 billion military aid package to Ukraine.