The government won't lightly give up its target of achieving a budget surplus in 2014/15 but it won't wreck the economy to get there, Prime Minister John Key says.

He admitted on Monday he was "a little bit less confident" about reaching the target than he was when the budget was presented on May 24.

Reserve Bank governor Alan Bollard last week said he thought it would take two years longer and released economic projections bleaker than the Treasury's.

"We're not going to do it come hell or high water," Mr Key said on Monday.

"Long term forecasts are very fickle...we're trying to drill into what's behind Alan Bollard's numbers."

Mr Key says he can't see anything the government could do differently to improve the situation.

"We wouldn't change anything, as of today."

He doesn't think the asset sales programme for the partial privatisation of four state-owned energy companies will be put on hold if the domestic or international situation weakens, and says equity markets are still strong.