Canada's main stock index slipped on Tuesday, dragged down by communication sector losses, as investors grew cautious ahead of U.S. President Donald Trump’s anticipated announcement of reciprocal tariffs.

The S&P/TSX Composite Index (.GSPTSE) fell 0.45% to 24,806.62 points as markets awaited details on Trump's plan to align U.S. tariffs with those imposed by other countries. Reports suggest White House aides have drafted proposals for 20% tariffs on a vast portion of the $3 trillion worth of goods imported annually into the U.S.

"If tariffs approach that level, it would significantly impact U.S. consumers' purchasing power, effectively acting as a major tax hike and a headwind for U.S. economic growth," said Douglas Porter, chief economist at BMO Capital Markets. "Canada, too, will feel the strain, as selling into the U.S. becomes more challenging."

Among the hardest-hit sectors, the capped communication index (.GSPTTTS) dropped 1.7%, with Rogers Communications (RCIb.TO) tumbling nearly 5% after Scotiabank downgraded its rating. The financial sector (.SPTTFS) also slid 0.7%.

On a positive note, consumer staples (.GSPTTCS) extended their gains for a fourth consecutive session, rising 0.43%. Interest rate-sensitive real estate (.GSPTTRE) edged up 0.1%, while utilities (.GSPTTUT) gained as government bond yields fell for the fourth straight day.

Meanwhile, fresh economic data released on Monday indicated that Canada’s manufacturing sector contracted at an accelerated pace in March, adding further pressure on the market.