A scuffle broke out between Chinese and US officials over the "nuclear football" — the briefcase containing the US nuclear launch codes — during a visit to Beijing by US President Donald Trump last year, according to media reports.
US news website Axios said multiple sources confirmed an incident in which Chinese officials tried to block a military aide with the briefcase from following Mr Trump into the Great Hall of the People, despite the aide being required to stay close to the President at all times.
The report said when Mr Trump's chief of staff Mike Kelly attempted to intervene, a Chinese official tried to grab him before a US Secret Service agent tackled the Chinese official to the ground.
The Secret Service did not initially deny the incident took place, but in a tweet said reports that a host nation official was "tackled" to the ground were "false".
The federal law enforcement agency later confirmed an incident had taken place.
"An individual, not part of the official delegation, attempted to prevent one of our protectees from entering a room," Secret Service spokesman Cody Starken said in a statement to Axios.
"A US Secret Service agent quickly intervened and a short scuffle ensued.
"The individual complied with the agent's directions and no further action was necessary."
White House press secretary Sarah Huckabee Sanders also confirmed "a quick scuffle ensued and the individual was detained", according to Axios.
It is believed at no point did the Chinese have the briefcase in their possession, or even touch it.
The "nuclear football" is a leather briefcase that contains the codes needed to launch a nuclear strike while away from fixed command centres.
It is carried by a rotating group of military officers near the President whenever he is travelling.
