WASHINGTON (Reuters) - Republican vice presidential nominee Paul Ryan said on Friday that another round of monetary stimulus from the U.S. Federal Reserve would be a bad idea.

Ryan's comments in an interview with CNBC came ahead of the Fed's September 12-13 meeting, where some economists think the policymakers will unveil another round of bond buying to prop up the country's weak economic recovery.

"All this easing is simply, in my opinion, the Federal Reserve trying to bailout bad fiscal policy," Ryan said. "I think the costs are clearly outweighing the benefits of this."

Ryan declined to comment on Republican presidential nominee Mitt Romney's position that, if elected, he would not reappoint Fed Chairman Ben Bernanke to a third term.

"I don't think it's appropriate to comment on what you do with personnel such as that," Ryan said. "I have known Ben a long time. He and I have disagreements on these issues, but (we) are respectful of one another."

Bernanke's second four-year term as chairman at the Fed ends January 31, 2014.

Many top Republicans have blasted the Fed's aggressive recession-fighting policies that involve ultra-low interest rates and purchases of billions of dollars in bonds and notes as overreaching and reckless.

Ryan has been a harsh critic of the Fed's loose monetary policy. He has backed legislation that would open up the Fed's monetary-policy decisions to congressional scrutiny and strip the central bank of its mission to seek maximum employment.

(Reporting by Jason Lange and Rachelle Younglai; Editing by Vicki Allen)