The US has expressed "regret" and termed "unfortunate" the interrogation of Pakistani Army officials at Dulles International Airport, but said that it has not officially apologised to Islamabad for the incident.
The US asserted that such incidents are bound to happen in the future given the nature of travel in the era of increased terrorist threat to air travel.
"It is hard to interpret exactly what happened on board the airplane. It was regrettable. We think that there was a misunderstanding, miscommunication between the Pakistani contingent and the aircrew," State Department spokesman P J Crowley told media persons at his daily news conference.
A nine-member group of high-ranking Pakistani officers boarded the United Airlines Flight 727 from Washington to Tampa late Sunday but were pulled off the plane after one of them "made a comment to a flight attendant," United spokesman Mike Trevino said.
All this started, when one of the delegates who -- weary of a long day of travel that began in Islamabad -- said, "I hope this is my last flight," or words to that effect.
"The delegation was subjected to unwarranted security checks at Washington airport by the US Transport Security Agency," the Pakistan Army said in a statement.
"However, as a result of these checks, military authorities in Pakistan decided to cancel the visit and called the delegation back," it said.
"It is regrettable. Unfortunately, it is the environment that we find ourselves when it comes to air travel these days," Crowley told media persons.
"All of us are subject to air travel and it's become a lot less fun than it used to be. But this is something that happens day in and day out to Americans and Pakistanis and the citizens of other countries," he added.
"We've already had conversations. We're going to have more conversations with Pakistan regarding this incident," Crowley said.
Earlier, the Department of Defence (DoD) denied reports that either Pentagon or the CENTCOM have apologised for the incident.
"I can't speak for the entire Department. If some individuals told them that I am sorry, that is different than a DoD apology. But I do not want to rule out that someone in the Department might have talked to them," Pentagon spokesman Dave Lapan told reporters.
"That was an unfortunate incident that these gentlemen were coming here to participate in a conference in CENTCOM," Lapan said, adding that he does not have all the facts of the incident and cannot rule anything out.