Consumer confidence improved in June from three months earlier for the second quarter in a row in a sign that the nation's export-driven upswing is improving sentiment, a government survey showed Tuesday.

The survey by the Cabinet Office found that the consumer confidence index as of June 15 rose by 0.9 point to 39.3 on a seasonally adjusted basis from 38.4 in the previous survey in March, when it rose 1.5 points.

But a Cabinet official remained cautious about future prospects for the economy, partly because the poll was taken before the recent plunge in U.S. equity prices in the United States, Japan's major export market.