Japan's central bank wrapped up its final meeting of the year Tuesday on an upbeat note, citing signs of improvement in exports, investment and industrial production, while keeping its ultra-lax monetary policy unchanged.

The Bank of Japan said Tuesday that its key policy interest rate would stay at negative 0.1 percent.

The U.S. Federal Reserve is raising interest rates as the U.S. recovery gains momentum. But the BOJ says it will persist with its use of asset purchases and ultra-low interest rates as long as necessary to jolt Japan, the world's third-largest economy, out of stagnation.

The policy statement issued by the BOJ after it wrapped up its two-day meeting said that slowing growth in China and other emerging markets, Britain's plan to leave the European Union and the impact of changing U.S. policy on financial markets were key risks.