The loonie had rebounded on Friday from a 14-month low as US oil prices bounced back from levels not seen in five months. Canada is a major producer of commodities, including oil and metals.

Copper prices slid to a four-month low after data showed a sharp drop in imports into China, the world's biggest consumer, feeding pessimism about demand following hefty inflows into London Metal Exchange inventories last week.

US crude prices were up 0.69 percent to $46.54 a barrel as news that Organization of the Petroleum Exporting Countries and other producers may extend production cuts offset rising US drilling.

At 9:57 a.m. ET (1357 GMT), the Canadian dollar was trading at C$1.3691 to the greenback, or 73.04 US cents, down 0.3 percent, according to Reuters data.

The currency traded in a range of C$1.3644 to C$1.3720.

Losses for the loonie came after US Commerce Secretary Wilbur Ross said on Saturday that threats of retaliatory trade actions from Canadian officials were "inappropriate" and would not influence final US import duty determinations on Canadian softwood lumber.

Speculators have ramped up bearish bets on the Canadian dollar to the most since February 2016, data from the Commodity Futures Trading Commission and Reuters calculations showed on Friday. Canadian dollar net short positions rose to 47,704 contracts as of May 2 from 42,642 a week earlier.

Canadian government bond prices were lower across the yield curve, with the two-year price down 3 Canadian cents to yield 0.699 percent and the 10-year falling 13 Canadian cents to yield 1.557 percent.