American football stars took a knee in defiance of Donald trump at Wembley Stadium today after he said sportsmen who 'disrespect America' should be 'fired'. 

Players from both Jacksonville Jaguars and the Baltimore Ravens dropped to their knees as the national anthem was played prior to the match in London. 

No players were kneeling during the playing of 'God Save The Queen', which followed the Star Spangled Banner. 

They did so after President Trump had stoked tensions by saying NFL players who protested during the national anthem should be sacked by their team. 

At a rally on Friday night the president said: 'Wouldn't you love to see one of these NFL owners, when somebody disrespects our flag, to say, 'Get that son of a bi*ch off the field right now... he is fired.' 

He was referring to a controversial string of protests started by player Colin Kaepernick last year when he sat or kneeled during the anthem to highlight the treatment of black Americans. 

Players on both teams and Jaguars owner Shad Khan, who were not kneeling, remained locked arm-in-arm throughout the playing of the national anthem and 'God Save The Queen'. 

Khan, who also owns Championship football club Fulham, has previously donated one million US dollars to Trump's presidential inauguration. Shortly after the contest got under way at Wembley, the Ravens posted a message on Twitter which read: 'We recognise our players' influence. We respect their demonstration and support them 100 per cent. All voices need to be heard. That's democracy in its highest form.'

The Jaguars tweeted a photo of Khan standing, arm in arm with Lewis and Smith, with the caption 'Unity'.  

At a rally in Alabama on Friday night, Trump had delivered a scathing attack on NFL players who opt to kneel in protest when the Star-Spangled Banner is played prior to matches.

He claimed team owners should sack any player involved in such a demonstration and that fans should leave the stadium if they see it.

There was a fiery response from the NFL to Trump's controversial comments. NFL commissioner Roger Goodell released a statement saying 'divisive comments like these demonstrate an unfortunate lack of respect'. 

The NFL Players' Association said Trump had crossed a line by effectively telling players to just 'shut up and play'.

Association president Eric Winston said Trump's comments were 'a slap in the face to the civil rights heroes of the past and present'.