Moody's Investor Services says the outlook for New Zealand's rating remains stable, underpinned by low public debt and strong control of public finances.
New Zealand holds an AAA rating, and the credit rating agency notes this country did not suffer as badly during the global financial crisis as other similarly rated nations.
It says economic growth is likely to remain sound, though it will be subdued compared with the 3.3% expansion seen between 2000 - 2007, as households are less willing to take on extra debt.
The Canterbury earthquake on 4 September and failure of South Canterbury Finance on 31 July are not expected to significantly alter the Government's debt requirements.
Meanwhile, Finance Minister Bill English says tax changes on 1 October will add about 1% to economic growth over the next few years.
Personal income tax rates will be cut, and the Goods and Services Tax will rise from 12.5% to 15% on Friday.
Mr English says the changes will tilt the economy towards savings, investment and exports, and away from unsustainable borrowing, consumption and over investment in housing.