TORONTO, March 31 (Reuters) - The Canadian dollar weakened against its U.S. counterpart on Monday, giving back some monthly gains, as investors grew risk-averse ahead of U.S. trade tariffs expected to be unveiled this week.

The loonie was trading 0.5% lower at 1.4385 per U.S. dollar, or 69.52 U.S. cents, after touching its weakest intraday level since March 20 at 1.4395.

Global stocks fell and gold prices scaled new highs after U.S. President Donald Trump said on Sunday that reciprocal tariffs he is set to announce on Wednesday will include all nations.

"There has got to be a sense of risk aversion in the marketplace," said Amo Sahota, director at Klarity FX in San Francisco. "The Aussie and the Kiwi got hit pretty hard overnight in Asia marketplaces."

The Australian dollar weakened 0.7%, while the New Zealand dollar was trading 0.8% lower. Australia and New Zealand, like Canada, are major producers of commodities so their currencies tend to be sensitive to shifts in investor sentiment.

The price of oil, a major Canadian export, rose 3.2% to $71.58 a barrel after Trump threatened to impose more tariffs on Russia and to possibly attack Iran.

For March, the Canadian dollar was up 0.6%, extending its recovery from a 22-year low last month at 1.4793.

"The loonie overall had its initial moves very early on in the (trade war) cycle," Sahota said, adding that the focus has turned recently to how U.S. tariffs will impact other countries, such as those in Europe.

Speculators have reduced their bearish bets on the Canadian dollar to the least since October, U.S. Commodity Futures Trading Commission data released on Friday showed. As of March 25, net short positions had decreased to 129,534 contracts from 136,582 in the prior week.

Canadian government bond yields fell across the curve. The 10-year was down 1.7 basis points at 3.000%.

Reporting by Fergal Smith; Editing by Richard Chang