As long as the USA is part of ICAO, they should ADHERE to the STANDARD ICAO Phraseology or ask for OFFICIAL ICAO published amendments.
Don't like it Yanks? Then get the hell out of ICAO.
American Carriers ATC is absolutely horrible out of their own country. They do not want or know how to communicate in standard calls, do not understand standard instructions, even when told in very clear aviation English.
In the USA, Unless there is an OFFICIAL ICAO amendment, ATC HAS TO comply with standars ICAO phraseology, and especially so when dealing with International traffic. All the moaning about some carriers not having a clue what is said by atc in JFK, ORD, etc. is mostly NOT because of poor ATC disipline by the crews but by American controllers who do not get it that they are dealing with crews that are not local. speak slower, cut the slang and start being Professional!
And for those who think that Eurocontrol is in the Middle ages... on the contrary...US ATC is twenty years behind the equipment that most European ATC centres have, especially Eurocontrol, which has the most modern equipment in the World, together with Langen and Munchen. So get your facts right.