U.S. stock futures slipped and Treasury yields nudged higher after oil prices rose back above $100 a barrel.

Investors were unconvinced by reports of progress in talks between the U.S. and Iran. After trading around $99 a barrel earlier in the session, Brent crude contracts rose by 0.9% to $100.10 a barrel. West Texas Intermediate contracts nudged back above $90 a barrel. American and Iranian diplomats met in New York on the sidelines of the United Nations General Assembly, the first meeting between high-level representatives since June. U.S. President Trump told reporters the countries' delegations "had a very good meeting," after earlier telling the assembly that a deal wouldn't come until after the Midterm elections in November.

Meanwhile, diesel prices rose to fresh highs in the U.S. as the Trump administration mulled bans on diesel exports--a move opposed by oil executives, The Wall Street Journal reported.

Treasurys weakened across the yield curve as investors increasingly priced in near-term Federal Reserve rate hikes. That increased confidence lifted the dollar, which traded close to an eight-week high. Ten-year Treasury yields edged 1.4 basis points higher to 4.983%, while 30-year yields rose back above 5.300%. Two-year yields rose by 1.9 basis points to 4.794%.

Futures for major U.S. indexes all traded in the red after an erratic day of trade Tuesday. Dow Jones Industrial Average futures slipped 0.2%, while S&P 500 futures lost 0.1%. Nasdaq futures lost 0.25% as chip stocks weakened slightly in premarket trade, after the index closed at another record high Tuesday.

Investor concerns that artificial intelligence would empower consumers to switch providers caused a selloff in so-called "consumer inertia" stocks Tuesday, but the trade's main losers--including the New York Times and insurance group Allstate--were steady in premarket trade Wednesday.

Equity markets were mixed in Asia Wednesday, with indexes in mainland China and Hong Kong both falling, while South Korea's Kospi edged up 0.9%. Higher oil prices weighed on European equities, with the continent-wide Stoxx 600 reversing early gains to fall 0.5%.

Bitcoin slipped to fall below $86,000. Gold also pulled back, but prices remained above $4,300 a troy ounce.

For the day ahead, investors will continue to look for headlines generated by the General Assembly in New York. Progress over a de-escalation between Ukraine and Russia will be in focus.

Wheat and corn prices fell by around 1% in U.S. trade Wednesday morning, following reports that officials from the U.S., Europe and Ukraine were meeting to discuss proposals to offer Moscow.

September flash PMI data from across the globe are also due Wednesday, while Federal Reserve policymaker Michael Barr will speak later, too.