The British 'Up yours', back of the hand 2 finger salute may not be under stood in The US, even at the Presidential level,

"In the United Kingdom, Ireland, Australia, and New Zealand, the V sign, when given with back of the hand towards the recipient,
serves a similar purpose. George H. W. Bush, President of the United States, accidentally made the gesture while on a diplomatic trip to Australia."


https://bshistorian.wordpress.com/2007/07/02/two-fingers-up-to-english-history/