(Corrects date consultations end to Sept. 6 from Sept. 5 in paragraph 2.)
* Futures down: Dow 0.40 pct, S&P 500 0.28 pct, Nasdaq 0.38 pct
By Shreyashi Sanyal
Sept 4 (Reuters) - U.S. stock index futures were lower on Tuesday following the Labor Day weekend, as trade talks with Canada ended last week with no deal to revamp the North American Free Trade Agreement (NAFTA) and on fears of potential China tariffs.
A fresh round of U.S tariffs on $200 billion worth of Chinese goods are expected to take effect in late September after a public comment period ends on Sept. 6.
U.S. President Donald Trump has told his aides he is ready to impose the tariffs as soon the public comment period ends, according to a Bloomberg report last week.
The world's two largest economies have already applied tariffs to $50 billion of each other's goods in a tit-for-tat trade war.
Talks between Canada and the United States to renegotiate the North American Free Trade Agreement (NAFTA) ended on a sour note on Friday as the two sides were unable to reach a deal.
U.S. and Canadian trade officials set plans to resume their talks on Wednesday with the aim of getting a renewed NAFTA deal.
The dollar rose nearly half a percent against a basket of major currencies.
At 7:43 a.m. ET, Dow e-minis were down 105 points, or 0.4 percent. S&P 500 e-minis were down 8 points, or 0.28 percent and Nasdaq 100 e-minis were down 28.75 points, or 0.38 percent.
Facebook fell 0.90 percent in premarket trading after brokerage MoffettNathanson downgraded the social media giant to "neutral."
Nike dropped 1.82 percent. The sportswear maker chose Colin Kaepernick, the first NFL player to kneel during the national anthem as a protest against racism, as one of the faces for advertisements commemorating the 30th anniversary of its "Just Do It" slogan.
Advanced Micro Devices gained 1.2 percent after two brokerages hiked price targets on the chipmaker's shares.
Data from the Institute for Supply Management on national factory activity index is expected at 10 a.m. ET. (Reporting by Shreyashi Sanyal in Bengaluru; Editing by Shounak Dasgupta)