Argentina players Lisandro Martinez and Giovani Lo Celso sparked controversy after their World Cup semifinal victory over England by waving a banner thrown onto the pitch by fans declaring sovereignty over the Falkland Islands.
The banner read, "Las Malvinas Son Argentinas", meaning "The Falklands are Argentinian."
According to Al Jazeera, the dispute dates back to 1816, when Argentina claims it inherited the islands from Spain after gaining independence.
Britain took control of the territory in 1833, a move Argentina considers illegal.
The South Atlantic islands, known as the Falklands in the UK and the Malvinas in Argentina, have remained a source of diplomatic tension for decades.
The dispute escalated into the 1982 Falklands War, which claimed the lives of 649 Argentine and 255 British soldiers.
Although Britain emerged victorious and most of the islands' residents identify as British, the issue remains highly sensitive, as demonstrated during the World Cup semifinal.
The players' actions appeared to breach FIFA and the International Football Association Board (IFAB) regulations, which prohibit political, religious, or personal messages on the field.
The incident came despite prior warnings from security officials, who had anticipated heightened tensions.
Before the match, Argentina's Security Minister said flags and banners relating to the islands' sovereignty would not be allowed inside the stadium, in line with FIFA regulations.
The political row intensified after Argentina's Vice President Victoria Villarruel posted messages on X before the match, suggesting the rivalry extended beyond football and accusing Britain of occupying Argentine territory and exploiting its resources.
"The Falklands are Argentine. They banned bringing them to the stadium and forgot that we carry them in our blood and our hearts," she wrote.
After Argentina's 2-1 victory, Villarruel shared a video, seen by TNX Africa, showing Argentine troops during the 1982 war.
She captioned it: "Argentina World Cup finalist! Thank you Enzo, thank you Lautaro, thank you Argentina National Team for giving us one more joy! It wasn't just another match!"
Speaking to the BBC, British Business and Trade Secretary Peter Kyle described the banner as "completely unacceptable" and said he expected FIFA to investigate.
"I think an investigation is certain to happen because it was such an egregious violation of the rules of not having political activity as part of football," he said.
Argentina has previously faced backlash for controversial behaviour.
After the 2024 Copa America, midfielder Enzo Fernandez livestreamed the team singing a discriminatory chant about French players.
This prompted a legal complaint from the French Football Federation and led to the firing of Argentina's sports undersecretary, Julio Garro, who had suggested Lionel Messi apologise.