At 9:37 a.m. ET (14:37 GMT), the Toronto Stock Exchange's S&P/TSX composite index was up 15.01 points, or 0.1 percent, at 15,648.34.

China struck an upbeat note as the trade talks resumed on Monday, but it also expressed anger at a US Navy mission through the disputed South China Sea, casting a shadow over the prospect for improved Beijing-Washington ties.

Eight of the index's 11 major sectors were higher.

Energy stocks dropped 0.9 percent as US crude prices were down 2.3 percent per barrel, while Brent crude lost 1.2 percent.

An uptick in US drilling and concerns over demand due to the slow progress in US-Chinese trade talks weighed on oil prices.

The financials sector edged up 0.2 percent, while the industrials sector marginally rose 0.3 percent.

The materials sector, which includes precious and base metals miners and fertilizer companies, shed 0.3 percent. Gold futures fell 0.6 percent to $1,306 an ounce.

On the TSX, 117 issues were higher, while 114 issues declined for a 1.03-to-1 ratio favouring gainers, with traded volume touching 11.44 million shares.

The largest percentage gainer on the TSX were Restaurant Brands, which rose 3.7 percent after reporting better-than-expected profit and raising its 2019 dividend.

Canada Goose Holdings Inc, which rose 2.7 percent, was the second biggest gainer.

SNC-Lavalin Group Inc fell 5.8 percent, the most on the TSX, after the construction and engineering firm cut its full-year profit forecast due to mining dispute in Latin America.

The second biggest decliner was Seven Generations Energy Ltd, down 3.1 percent.

The most heavily traded shares by volume were Aurora Cannabis, Supreme Cannabis Co and Aphria Inc .

The TSX posted eight new 52-week highs and one new low.

Across all Canadian issues, there were 17 new 52-week highs and three new lows, with total volume touching 21.56 million shares.