Apple has warned that proposed tariffs on imports of iPhones and its other flagship products from China to the US would "tilt the playing field" in favour of its overseas rivals and dent its multibillion-dollar contribution to the American economy.

The iPhone maker's stark warning is just one of hundreds of submissions to the US Trade Representative from global manufacturers, small businesses and individual Americans, many of them in vehement opposition to the Trump administration's proposed rise in import duties.

In a letter that was made public on Thursday, Apple pressed the White House to abandon tariffs of up to