Earlier this month, Mr Key said he would be open to the possibility - which has been previously floated - about sending kiwi in return for pandas if it helped close or bring down the price of a deal.
As well as putting up taxpayer money, he could also talk to Chinese President Xi Jinping in an attempt to bring giant pandas here.
Speaking from New York today, where he is attending a United Nations General Assembly week with other world leaders, Mr Key said he had not yet had a chance to meet the Chinese President.
Pandas would not be his number one issue if a meeting did happen, but he was sure he would have the discussion at some point.
Mr Key said he was unaware Mr Brownlee was delivering the panda proposal.
"But in the end...there is nothing new in terms of the Government's perspective, which is we think it would be a nice thing for New Zealand to have, but ultimately what level of contribution we'd be willing to make and whether that's going to move us up the queue, I don't know.
"They [giant pandas] are popular and there is a lot of demand for them."
Mr Key said having a minister such as Mr Brownlee deliver the proposal could help, "but I have also spoken to them about it in the past and so far pandas haven't turned up".
Wellington City Council is to look at a business case for bringing the animals from China to Wellington Zoo, but one councillor who is opposed believes the project could cost up to $100 million.
If the council came up with a proposal the Government would likely commit funds to help out.
In 2010 Mr Key raised the possibility of a deal with China in which giant pandas would be lent to a New Zealand zoo, but the Christchurch earthquakes the following year put that project on the backburner.
Mr Key has said Wellington Zoo had in the past been keen on the idea, but Auckland was not interested.