President Donald Trump has said he will not watch National Football League (NFL) or U.S. soccer team matches if players do not stand for the national anthem.The U.S. Soccer Federation last week said it had dropped its requirement that players stand during the anthem, saying the policy was wrong and detracted from the Black Lives Matter movement.The policy was adopted in 2017 after U.S. women’s national team member Megan Rapinoe took a knee during the anthem before a game, in solidarity with NFL quarterback Colin Kaepernick, who in 2016 started kneeling in protest of a flag he said represents...