International credit ratings agency Fitch has revised New Zealand's AA sovereign rating outlook from stable to positive in a move welcomed by the government Wednesday, despite concerns about the country's high external debt and dependence on commodities.

In a notice issued in New York on Tuesday local time, Fitch Ratings said the government's fiscal consolidation drive continued to be strong and Fitch believed it was supported across the political spectrum, a signal that Fitch believes the general election in September will not significantly change the fiscal performance.

It noted the government was on course for an operating surplus in the 2014-2015 fiscal year, the first since 2008, and that GDP growth was 2.7 percent last year and was expected to hit 3.8 percent this year.

However, inflationary pressures were growing, and the " persistent current account deficit, the need for foreign capital and net external indebtedness" were longstanding weaknesses that were expected to persist, with net external debt forecast to rise moderately to 72 percent of GDP by 2016 from 65.5 percent in 2013.

New Zealand's economy had large, growing and connected "twin concentrations" in dairy exports and in exports to China, that made it vulnerable to a slowdown in China, and its dairy exports were also vulnerable to the risk of "a sudden dent in reputation" such as a serious health issue.

Finance Minister Bill English said Wednesday that the government was making some good progress in addressing both the current account deficit and the external debt, which had both diminished over the last five years.

"And Fitch comments that New Zealand's economic policy framework, business environment and standards of governance rank among the world's strongest from a credit perspective, warranting 'high grade' sovereign ratings," English said in a statement.

Alongside Fitch's AA rating with a positive outlook, New Zealand was rated Aaa with a stable outlook by Moody's and AA with a stable outlook by Standard and Poor's.