The trip came as a New Yorker magazine report said the Bush administration was stepping up plans for a possible airstrike against Iran, even as it publicly pushes for a peaceful solution to the standoff.

"This White House believes that the only way to solve the problem is to change the power structure in Iran, and that means war," Hersh quotes an unidentified senior Pentagon advisor as saying.

The White House, without denying the report, reiterated that it was pursuing a diplomatic solution.