TOKYO, Feb 17 (Reuters) - Policymakers need more data on economic activity and lending to judge the impact of the Bank of Japan’s surprise adoption of negative interest rates last month, Japanese Economy Minister Nobuteru Ishihara said on Wednesday.

Since the BOJ took such a bold step, it is important for the government to work with the central bank to ensure the economy grows and does not return to deflation, Ishihara told reporters in a group interview.

The risk of a return to deflation still cannot be ruled out, so the government should focus on implementing a stimulus package recently passed in parliament and then pass the state budget for the next fiscal year, Ishihara said.

Ishihara also said the government’s plan to raise the sales tax next year to 10 percent from 8 percent is important for fiscal discipline, but implementation becomes a political decision if there is a big shock to the economy. (Reporting by Stanley White; Editing by Chris Gallagher)