"William Hague was pretty wide-ranging [on issues], everything from what's happening in Libya right through to Syria, but obviously in terms of the economic front... I think he is cautious like everyone else."
Despite London's rain and maximum 12C temperature, Mr Key described the pageant as "wonderful".
"It was just a great display of how wonderful the monarchy is in this country," he said.
"The river was lined from one end to the other and in the middle of all of it was the waka and of course two other craft from New Zealand, so a wonderful celebration for our country as well."
On Wednesday he and wife Bronagh will meet with the Queen.
"It will be a great opportunity obviously to pass on the best wishes of the people of New Zealand, congratulate her and thank her for her leadership over the last 60 years," Mr Key said.
Mr Key defended the Queen's association with New Zealand, and her 10 visits to the country during her reign.
"I would say it is a very significant contribution," he said of the Queen's visits to New Zealand.
"And there are other members of the royal family who have been out during that time.
"She has always shown a great affection for New Zealand, it's very genuine. She loves the country, she likes the people. She feels very much at home there and I think it's a genuine bond."
Mr Key said he will take a gift for the Queen when he visits.
"We are taking a gift of New Zealand cheeses. Something practical."
The prime minister will spend Monday in Brussels for a series of talks including meeting with NATO and European parliamentary leaders, before returning to London.
- AAP
