By Howard Schneider WASHINGTON, April 27 (Reuters) - Federal Reserve policymakers will gather in Washington this week in what may be Jerome Powell's last meeting as head of the U.S. central bank, with energy prices still elevated and the Iran war at a standstill and likely to prolong uncertainty about the economic and monetary policy outlook.

President Trump's pick for Federal Reserve chair, Kevin Warsh, could shift how the central bank understands its power.