As international oil prices rose, US-listed energy stocks gained in premarket trading: Schlumberger (SLB.N), Occidental Petroleum (OXY.N) and ExxonMobil (XOM.N) were up 1.2%, while ConocoPhillips (COP.N) and Chevron (CVX.N) rose 1%.

Sepah News, the media arm of Iran's Islamic Revolutionary Guard Corps, quoted Iran's deputy foreign minister responding to an overnight US strike on Larak Island. He said foreign forces must leave the region and should be taught a deep lesson so they do not repeat acts of aggression.

Thomas Hempel, head of macro and market research at France-based Generali Asset Management, said in a note the case for a Fed rate hike in September remains finely balanced, so the firm remains cautious on long-duration bonds. He said the view that the Fed will raise rates once after the midterm elections is closely contested; stickier July core PCE and hawkish remarks at Jackson Hole by Fed chair Kevin Warsh have raised the risk of an earlier hike. Generali expects long-term Treasuries to range trade but sees the balance of risk to US long yields tilted to the upside.