A pharmaceutical executive collapsed unexpectedly while standing beside US President Donald Trump during a White House event centered on weight-loss medication.

The man’s legs appeared to give way, prompting those nearby to catch him and prevent any head injury.

Video footage from the incident in the Oval Office on Thursday (Friday AEDT) shows Trump rising from his desk to observe as a White House medical professional rushed to assist.

The individual was later identified as Gordon Finlay, a high-ranking executive at the Swiss pharmaceutical company Novo Nordisk.

White House officials swiftly cleared reporters and camera crews from the Oval Office following the incident.

Press Secretary Karoline Leavitt said in a statement: “During the Most Favored Nations Oval Office Announcement, a representative with one of the companies fainted. The White House Medical Unit quickly jumped into action, and the gentleman is okay. The Press Conference will resume shortly.”

The drama came as Trump unveiled a deal with drug companies Eli Lilly and Novo Nordisk to expand coverage and reduce prices for the popular obesity treatments Zepbound and Wegovy.

Known as GLP-1 receptor agonists, the drugs have soared in popularity in recent years but patient access has been a consistent problem because of their cost – about $US500 ($770) a month for higher doses – and medical insurance coverage has been patchy.

More than 100 million American adults have obesity, according to federal government estimates.

Starting doses of new, pill versions of the treatments also will cost $US149 a month if they are approved.

“(It) will save lives, improve the health of millions and millions of Americans,” said Trump, in an Oval Office announcement in which he referred to GLP-1s as a “fat drug.”