As President Donald Trump and his advisers begin weighing replacements for Federal Reserve Chair Jerome Powell, they’re running into one significant complication: It’s not clear that Powell will leave the US central bank next year.

Donald Trump, in a social-media post, said Fed chairman Jerome Powell should “resign immediately.” It was an escalation of his public complaints about Powell, who Trump believes is keeping interest rates high for no reason.

President Trump says Fed rate cuts would save the government as much as $900 billion a year in interest payments on its debt. Is that fight?