Major U.S. stock indexes opened lower Monday after President Donald Trump's tariffs on Canada, Mexico and China triggered a trade war.

Wall Street shifted lower in early trading Wednesday as markets took in more corporate earnings reports while considering the impact of tariffs being imposed by the United States and China.

U.S. stock futures and the dollar fell on Tuesday, while Hong Kong shares slipped from two-month highs, as the U.S. and China went tit-for-tat on tariffs and raised the spectre of a broader, damaging trade conflict.