U.S. stocks posted a fourth consecutive weekly decline as the Trump administration’s escalating trade spats threatened to upend economic growth.

The S&P; 500 sank 2.6 percent in the holiday shortened week, capping a 6.6 percent decline in May, its first down month this year. The Dow Jones industrial average dropped 3 percent to 24,815, its lowest close since late January. The Nasdaq Composite Index fell 2.4 percent.

Financial markets have been roiled since May 5, when President Trump touched off the latest flare-up in a U.S.-China trade war that many investors had seen as nearing a resolution. Concern deepened this past week as the president threatened to place tariffs on Mexican goods until that country stops immigrants from entering the U.S. illegally. On top of that, China said it’s preparing a blacklist of foreign companies it accuses of damaging its interests.

All 11 main S&P; 500 industry groups fell, with energy stocks declining the most as oil prices sank on concern the worsening trade tension will hurt demand. Automakers Ford Motor Co. and General Motors Co., which are particularly susceptible to tariffs, each dropped more than 3 percent.

The U.S. Treasury will sell $36 billion of three-month bills and $36 billion of six-month bills on Monday. It will also sell four-week bills and eight-week bills on Thursday.

— Bloomberg News