President Donald Trump and First Lady Melania Trump experienced an unexpected mishap at the United Nations on Tuesday when an escalator carrying them suddenly stopped, forcing the couple to walk up the stalled machine before Trump’s scheduled address to world leaders.

The incident, which occurred just before 10 a.m. at UN headquarters in New York City, prompted White House Press Secretary Karoline Leavitt to call for an immediate investigation.

“If someone at the UN intentionally stopped the escalator as the President and First Lady were stepping on, they need to be fired and investigated immediately,” Leavitt wrote on X, citing a report from The Times of London that UN staffers had previously joked about cutting off access to escalators and elevators for Trump’s arrival.

In an appearance later that evening on Fox News’s Jesse Watters Primetime, Leavitt suggested the malfunction “appears” to be sabotage, pointing to reports that some UN employees had mocked Trump’s visit.

“If we find that these were UN staffers who were purposefully trying to trip up, literally trip up the president and the first lady of the United States, well there better be accountability,” she said.

The U.S. Secret Service is also reviewing the matter, according to Leavitt.

United Nations officials, however, quickly dismissed speculation of intentional wrongdoing. Stéphane Dujarric, spokesman for Secretary-General António Guterres, told reporters the stoppage was caused by a safety feature.