Washington (CNN) -- U.S. relations with Pakistan in the wake of last month's NATO attack on a border post are "a mess," America's highest-ranking officer said Friday.
The chairman of the Joint Chiefs of Staff, Gen. Martin Dempsey, dismissed Pakistani government claims that the attack was planned.
"What I can say, absolutely, and I can't imagine anyone in this room wouldn't believe me: We did not attack a border post, a Pakistan military border post, intentionally," Dempsey said in a speech in Washington. "If you think we did, I'd have to ask you in return, what in the world would we hope to gain by doing that? So I can say that categorically.
"They believe we did this intentionally in some way to either discredit them or goad them into further action," Dempsey said of the Pakistani motivation for making the claim.
The American general said that sometimes, the U.S. is a victim of its own success, with the world overestimating U.S. military capabilities in the midst of the confusion of war.
"The rest of the world sees us as completely all-knowing, all-seeing, completely precise," Dempsey said. "You know, look, warfare is really, when you really get down and touch it, it's just ugly, and it's messy, and it's unpredictable, and it's chaotic, and there's fog, and there's friction."
Dempsey said the U.S.-Pakistan relationship is strained, but the U.S. is giving it time.
"What we're trying to do is show some patience, asking them to show some patience, and then we'll try to get back in touch with each other and see if we can work through it," he said. "But yeah, it is a mess."
Dempsey's unusually strong words and undiplomatic language were echoed at the Pentagon by spokesman George Little.
"This incident was not, I repeat not, a deliberate attack on the Pakistani military by (the International Security Assistance Force)," Little said. "It is wrong to assert that."
And these strong comments are coming from American officials even before the conclusion of the formal investigation into what happened when 24 Pakistani soldiers were killed.
"We know enough at this point to say with certainty this was not an intentional attack on Pakistani forces," Little insisted. "The Pakistanis are our partners. It defies reason that we would attack them."
Little was asked whether Defense Secretary Leon Panetta would agree with Dempsey on U.S.-Pakistan relations.
"It certainly is in a rough patch. You can ask the secretary at some point what term he would use," he said. "But if 'mess' describes a very difficult time in the relationship, the answer is absolutely yes."
Despite the chill in the relationship, the U.S. continues to work in a reduced fashion with Pakistan at special border coordination posts that had been set up to avoid an attack like the deadly one November 25, even though Pakistan had reduced its manpower at the border coordination centers.
Little said those shared posts were still making a difference.
"There have been instances of cooperation since the recent incident," he said. "It is important that they be fully manned so that we avoid similar incidents in the future."
And Dempsey hinted that the U.S. is considering alternatives to supply U.S. troops in Afghanistan if Pakistan continues to block road access through two border crossings.
"We're adapting to some of the things they've done, you know, the closures of the ground lines of communications and so forth," he said. "We're assessing the cost of that. There is a cost."