China's stocks and currency came under pressure as markets returning from a week-long break were greeted by a new trade dispute with the United States and ructions in the global artificial intelligence sector.

The first punches have been thrown between the United States and China in what could amount to a short-lived trade dispute with limited economic fallout or the start of yet another lengthy and painful trade war reminiscent of President Donald Trump’s first term.

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.