Nouriel Roubini says a hard-landing recession or entrenched inflation are the only 2 possible outcomes as the Fed battles a 'trilemma'

• Solving the US economy's financial issues with only Fed tightening looks like "Mission Impossible," Nouriel Roubini said.
• The Fed's current approach will result in either a recession or entrenched inflation.
• "So either a hard landing and a financial crash or de-anchoring of inflation expectations."

The Federal Reserve has been tasked to settle the US economy's precarious financial conditions, but the central bank's current approach will likely result in either a recession or views for more entrenched inflation, Nouriel Roubini said. 

The "Dr. Doom" economist said the Fed is up against the ultimate "trilemma" of trying to achieve price stability, growth stability, and financial stability using just one policy tool — tweaking the federal funds rate.