Police have arrested four Greenpeace protesters who scaled a large crane on a work site behind Parliament to unfurl a banner ahead of US Secretary of State Rex Tillerson's visit.
Mr Tillerson, a former head of the oil company Exxon, was in Wellington for a whistlestop visit to meet with Foreign Minister Gerry Brownlee and Prime Minister Bill English.
The withdrawal of the US from the Paris climate accord, announced by President Donald Trump last week, was among the topics discussed.
The protesters were on the crane at 7am, and hung a large banner reading, "Climate denial, huge mistake! RESIST."
Mr English said New Zealand had voiced its disagreement to the US position at their meeting.
About 200 people also protested on the ground nearby, in a rally organised by climate group 350 Aotearoa.
With umbrellas in one hand and placards in the other, the group was drenched as they turned up to protest in the rain outside the front lawn in Parliament.
350 Aotearoa chairman Aaron Packard said Mr English needed to send a stronger message and threaten to bring in sanctions against the US.
"Over a hundred mayors and leaders of states have stepped up to say they're going to fill in the gap to where Trump has pulled out. So [Mr English] needs to put pressure and show there is direct consequences of pulling out of the Paris Agreement."
At the protest, Greenpeace climate campaigner Kate Simcock told the crowd it was important they stood up for the planet, and their message to the government was clear.
"Take real climate action, that means stop looking for deep sea oil, it means stop burning coal, stop intensifying dairy."
Labour MP Grant Robertson said the government's response so far was weak.
"[Deputy Prime Minister] Paula Bennett did say it was disappointing - that's a joke.
"It's not disappointing... it's immoral and it is a crime against future generations."
Protesters also brought along a lifesize mannequin of Mr Trump and encouraged people to throw waterbombs and objects at it.
Green co-leader James Shaw told the crowd it was clear this was an issue New Zealanders cared about.
"I'm inspired by the fact that you've chosen to come out here in the cold and wet and condemn the American actions on the day that Rex Tillerson, T-Rex, the dinosaur, is visiting New Zealand."