John Kirby, coordinator of strategic communications at the National Security Council, said this in an interview with CNN.
According to him, Washington does not want to encourage or condone Ukraine's attacks inside Russia, because it does not want an escalation of the conflict.
He added that if the conflict escalates into a war between Russia and the West, it "will lead to much greater suffering on the European continent."
Kirby said that the United States has obtained assurances from the Ukrainian side that Western weapons will not be used for attacks inside Russia.
"But when it comes to them (to the Ukrainians. - RT), it belongs to them, "RIA Novosti quoted him as saying.
Kirby also said that the Ukrainian army is going to launch a counteroffensive in the summer.