TOKYO (Reuters) - Bank of Japan Governor Haruhiko Kuroda said on Tuesday the recent stock price rally reflected market optimism over the global economic outlook, brushing aside views its ultra-loose monetary policy was fuelling an asset price bubble. Kuroda said the central bank would be vigilant for financial risks associated with prolonged easing, nodding to growing concern among some lawmakers that prolonged easing was sowing the seeds of a bubble. But he stressed that it was premature to debate an exit from super-loose policy including the BOJ’s huge purchases and holdings of exchange-traded funds (ETF), as the coronavirus pandemic continues to ravage the economy. “It’s likely to take significant time to achieve our price (inflation) target. As such, now is not the time to think about an exit including from our ETF buying,” Kuroda told parliament. The BOJ has unveiled a plan to review its policy tools, including its ETF-buying programme, in March to make it more sustainable as the pandemic forces it to maintain its stimulus for a prolonged period. The plan reflects a growing concern among policymakers over the rising cost of extended easing. Some analysts also criticize the BOJ for continuing its huge ETF buying at a time Tokyo stock prices have set new highs. Kuroda said it was hard to predict whether stock markets were in a bubble. “Optimism over the global economic outlook and steady vaccine rollouts may be behind the recent surge in stock prices,” Kuroda said. “But the global outlook remains highly uncertain,” he said, adding that risks to Japan’s economy remained skewed to the downside.