Wall Street futures largely pointed sideways pre-bell Tuesday after three trading days in the green, and as investors sought clarity regarding a possible Persian Gulf peace deal.
In the futures, the S&P 500 was steady, the Nasdaq inclined 0.2% and the Dow Jones was up 0.1%.
West Texas Intermediate crude oil traded down 2.7% at $78.55 a barrel, striking below $80 for the first time since March.
Investors will also go on watch as the Federal Reserve starts a two-day policy session, the first helmed by new Chairman Kevin Warsh, to conclude with a rate announcement 2 pm ET Wednesday.
There is a 99.4% chance the central bank will keep rates unchanged, according to the CME Group's FedWatch tool, but pundits will pay close attention to Warsh's first post-announcement press conference, at 2:30 pm, for clues to the chair's leanings.
Asian exchanges traded unevenly higher overnight, although a raft of soft economic reports from Beijing undercut equity markets in Shanghai and Hong Kong.
European bourses tracked moderately higher midday on the continent.
On the economic calendar, in addition to the start of the Fed policy session, is the May housing starts and permits bulletin, along with the May import and export prices report, both at 8:30 am ET.
In premarket action, Bitcoin traded at $66,630, and 10-year US Treasuries offered 4.43%. Spot gold commanded $4,344 an ounce.