US equity indexes fell in midday trading Tuesday, extending the steep declines from the previous session.

The Nasdaq Composite fell 0.4% to 17,395.1, the S&P 500 was down 0.9% to 5,567.2, and the Dow Jones Industrial Average traded 1.2% lower at 41,390.6. All sectors declined, with energy, healthcare, and industrials among the steepest.

The Nasdaq sank 4%, the S&P 500 dove 2.7%, and the Dow slumped 2.1% at the close on Monday amid concern the US economy is heading into a recession as the Trump administration raised trade barriers.

President Donald Trump now plans to double the tariffs to 50% on all steel and aluminum imports from Canada, starting Wednesday morning, in response to Ontario Premier Doug Ford's decision Monday to slap a 25% surcharge on all electricity Ontario ships to the US.

"This will go into effect tomorrow morning, March 12th. Also, Canada must immediately drop their anti-American farmer tariff of 250% to 390% on various US dairy products, which has long been considered outrageous," Trump said in a post on Truth Social.

Trump continued saying if Canada does not drop "other egregious, long time tariffs" he will substantially raise tariffs on cars imported from Canada.

In US economic news, job openings rose to 7.740 million in January, according to the Bureau of Labor Statistics, above the 7.6 million openings expected in a survey compiled by Bloomberg and up from 7.508 million reported in December.

Most US Treasury yields rose intraday, with the 10-year up 3.1 basis points to 4.24%, while the two-year rate stable at 3.90%, following the declines seen on Monday.