(Reuters) - Wall Street’s main indexes fell on Friday after President Donald Trump threatened to slap new tariffs on China over the coronavirus crisis, while a profit warning from Amazon added to the gloom. Trump said late on Thursday his trade deal with China was now of secondary importance to the pandemic, as his administration crafted retaliatory measures over the outbreak. The threat pulled attention back to the trade war between the world’s two largest economies that has kept global financial markets on tenterhooks for nearly two years.