Prime Minister John Key now says he is prepared to have a chat to actor Keisha Castle-Hughes over her stance on climate change.

On Tuesday he said that Castle-Hughes, who is an ambassador for Greenpeace's Sign On campaign, "should stick to acting".

In response Castle-Hughes said she would love to talk to him and maybe he would discover that she knew more than he thought she did.

She said the only message she wanted to send Mr Key was that it was the perfect time to commit New Zealand to the 40 per cent emission target.

Mr Key said his earlier comments were "rather flippant".