The economy is on a recovery track, although improving corporate sentiment is being challenged by high unemployment and persistent but mild deflation, the government said in its monthly economic assessment Friday.

"The economy has been picking up steadily," the Cabinet Office said in its April report, using the same phrase as last month. But it also said the economy is "weakly self-sustaining and remains in a difficult situation, such as a high unemployment rate."

The government upgraded its assessment of the economy for the first time in eight months in March. In the latest report, the Cabinet Office says business sentiment is "improving."

The robustness reflects the Bank of Japan's recent "tankan" business sentiment survey. The central bank said earlier this month that business confidence in the country continued to improve in the three months through March, helped by a rise in exports and production.