FIFA has called on the teams participating in the controversial Qatar World Cup to "focus on football" and stop "handing out moral lessons" in a letter revealed by Sky News on Thursday.

"Please let's now focus on the football!" FIFA president Gianni Infantino and secretary general Fatma Samoura said in a letter sent to all 32 World Cup teams. "We know football does not live in a vacuum and we are equally aware that there are many challenges and difficulties of a political nature all around the world. But please do not allow football to be dragged into every ideological or political battle that exists."

"One of the great strengths of the world is indeed its very diversity, and if inclusion means anything, it means having respect for that diversity," continued the FIFA letter. "No one people or culture or nation is 'better' than any other."