Vice President Pence abruptly canceled an event in New Hampshire on Tuesday to remain in Washington, but his office declined to provide any details about the decision.

The cancellation sparked intrigue Tuesday morning after a Pence aide told a New Hampshire crowd awaiting the vice president that Pence had been on his way but was called back for an emergency.

“Air Force 2 was heading this way, but there’s been an emergency callback; the vice president has been asked to return to Washington,” said Randy Gentry, a representative from Pence’s office, according to video posted on Twitter by Sean Colahan of NBC10 Boston.

Pence spokeswoman Alyssa Farah quickly responded on Twitter to clarify that Pence never left Washington and that his last-minute change of plans was not an “emergency callback.” But she declined to offer any other information about his whereabouts in Washington and why he canceled his trip.

"Something came up that required the @VP to remain in Washington, DC. It's no cause for alarm. He looks forward to rescheduling the trip to New Hampshire very soon," she tweeted.

Pence was on his plane and prepared to take off for New Hampshire when his chief of staff, Marc Short, decided to cancel the trip due to a security concern, according to administration officials familiar with the decision who spoke on the condition of anonymity to discuss the issue. The security concern was not a threat to Pence, according to two people close to him who declined to provide more details.

The officials said there was frustration among others in the vice president's office over how the decision was made and publicly explained, which left public speculation to fill the vacuum created by the lack of specifics provided. Short declined to comment.

Pence was supposed to leave for New Hampshire at 10:15 a.m., according to his daily guidance, to meet with patients at a recovery center about the opioid crisis and then deliver remarks.

Joel Goldstein, an expert on the vice presidency, said it was unusual for a vice president to cancel a trip without an explanation.

“If it’s nothing, you’d think you’d give an explanation unless it’s so minuscule you’re going to offend the people you’re stiffing,” Goldstein said. “It does seem bizarre that it would happen without an explanation.”

Pence has nothing on his schedule for Wednesday.

Ashley Parker contributed to this report.