The Prime Minister is optimistic about starting free-trade talks with the European Union just days before meeting European leaders in Brussels.
New Zealand has long sought to start trade negotiations with Europe but until now has met resistance.
But Mr Key said his meetings this week with the president of the European Council, Donald Trusk, and the president of the European Commission, Jean-Claude Juncker, were significant.
"Europe's been quite reluctant to do that for a long period of time but they are now much more open to progressing a deal with us and potentially Australia, although negotiating separately from what I can see. So it's very exciting from our point of view."
Mr Key said Europe was a key market for New Zealand, with two-way trade worth nearly $20 billion.
He said such a deal could sit alongside the just-signed Trans-Pacific Partnership agreement, the Korea free trade deal and other economic agreements New Zealand already had in place.
Mr Key said with the global talks at the World Trade Organisation continuing to struggle, New Zealand had to do what it could to broaden and strengthen its trade connections.
Before his meetings in Brussels he will be in Marrakech to chair a meeting of the executive committee of the International Democrat Union, the umbrella organisation for conservative political parties around the world.
Later in the week he will travel to London to meet his British counterpart, David Cameron.
He said Britain had been a strong supporter of New Zealand doing a trade deal with the EU.
Mr Key will also have an audience with the Queen.