National Security Council Spokesperson John Kirby speaks during a press briefing at the White House, on July 26, 2023, in Washington (AP)

The United States has provided Ukraine with all its demands for its counteroffensive, but progress is still slower than expected and it will be even harder with the coming fall, National Security Council Coordinator for Strategic Communications John Kirby pointed out on Thursday.

"In the months leading up to the counteroffensive, we fulfilled everything on the Ukrainian shopping list, everything they said they needed for the counteroffensive," Kirby told CNN.

He continued, "We're continuing to do that, we're continuing to willing to continue to train Ukrainian forces but more critically, we're giving them the kinds of tools and weapons that they need to break through those [Russian lines of defense]."

The White House official noted that the Ukrainians understand that "time is not on their side," and with the fall coming, it would be harder for them to maneuver on the ground and to operate drones and air security systems.

Kirby also suggested avoiding speculation on "what success looks like" and letting Kiev determine that.

Commenting on a recent CNN poll showing that over half of Americans oppose Congress authorizing additional funding to support Ukraine, Kirby said it would not change US President Joe Biden’s position on the matter.

"The President has said publicly, and he certainly said it privately to President Zelenskyy - and it's not just the president but other leaders of NATO and the G7 - that we're going to stay behind Ukraine for as long as it takes," the White House Spokesperson explained.

Elsewhere, Kirlby expressed confidence that the American people understand "what's at stake here."