Yen climbs for third straight session with traders on alert for intervention

Meanwhile, oil prices sank more than $4 a barrel after U.S. President Donald Trump held back from a fresh attack on Iran, undermining support for the safe-haven greenback. Iran said it is not currently holding talks with the United States.

Rising energy prices are expected to weigh more heavily on the economies of the euro zone and Japan, both large energy importers, while the United States is seen as relatively insulated from oil shocks.

The dollar index =USD was little changed at 99.79, having slid more than 1.5% last week. The euro was up 0.03% at $1.1525, after hitting a fresh 1-1/2-month high at $1.1559 in Asian trade.

“The fact that the dollar is not broadly weaker probably owes to the unresolved issue of whether the Federal Reserve will hike in September,” said Chris Turner, global head of forex at ING, after arguing that the drop in oil prices should weigh on the greenback.