President Donald Trump’s 10% baseline tariffs on US trading partners around the world came into effect on Saturday.Higher duties on some countries, which replace, rather than add to the 10% rate, are due to start on April 9.The tariffs raised US tariffs to their highest level in more than a century, causing a significant drop in the S&P 500 index.Trump indicated willingness to lower his duties if other nations offered him something 'phenomenal'.