The USA have withdrawn from the Under-17 World Cup in Qatar because of the risk of armed conflict.
In a letter sent to players and seen by news agency Reuters, US Soccer said it made the decision "in light of current circumstances".
It cited advice from the US Department of State, which issued a level three travel advisory, external for Qatar last month.
That came a day after Yemen's Houthi movement carried out a deadly attack on an airport in neighbouring Saudi Arabia, while air strikes have continued on Saudi Arabia and Yemen.
The 48-team tournament runs from 19 November to 13 December, and the USA were due to play group games against Montenegro, Chile and Algeria.
The US travel advisory mentioned Houthi attacks on civilian airports and critical infrastructure, and warned that hostilities "have the potential to escalate rapidly beyond that immediate area".
The update told Americans to reconsider travel to Qatar because of "risk of armed conflict".
"The well-being of our players and staff will always be our top priority," US Soccer said in the letter.
It said it would notify the players' clubs and asked players not to comment publicly until their withdrawal has been announced by tournament organisers Fifa.
The 2027 Asian Cup - Asia's version of the European Championships - was due to take place in Saudi Arabia from 7 January to 5 February, but has been postponed by almost a year because of the conflict.
The wife of England striker Ollie Watkins, who plays in the Saudi Pro League, has taken their children back to the UK until the situation "calms down".
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