WASHINGTON, July 25 (Reuters) - U.S. President Donald Trump is unlikely to follow through on his threat to place 100% tariffs on countries that buy Russian oil because it would worsen politically-damaging inflation pressures and his similar threat against buyers of Venezuelan oil has had limited success, especially in China.

Brazil is scrambling to avert punishing 50% U.S. tariffs in a week's time, but high level talks are stalled and U.S. companies are reluctant to confront U.S. President Donald Trump over the issue, officials and industry leaders say.