Luxon has landed in Washington DC to both literal heat and political heat: the temperatures are in the mid-30s as a heatwave hits parts of the US. It matches the political heat – the lead-up to the summit has been dominated by pressure on Biden to step down as the Democrats’ candidate for President in the November elections – and by Biden’s return fire, disputing rumours he is unwell and saying he is determined to stay to try to fend off Donald Trump.

It is the first time DC has hosted the North Atlantic Treaty Organization (Nato) Summit in 25 years, and the timing ensures there will be a lot of focus on Biden’s hosting of it – from the dinner at the White House to the main summit event and press conference. The leaders inside will also be focused on Biden and Trump, due to Trump’s less enthusiastic views of Nato.

It will be attended by leaders from the 32 member states, as well as Ukraine’s President Volodymyr Zelenskyy.

Luxon can expect formal bilateral meetings with a number of those leaders, including two who knew former PM Jacinda Ardern well – Canada’s PM Justin Trudeau and French President Emmanuel Macron, who partnered with Ardern on the Christchurch Call. It is uncertain whether new British Prime Minister Keir Starmer will see him.

The Russian war on Ukraine will again be the focus of the summit – the recent bombing of a children’s hospital in Kyiv has been highlighted ahead of the Summit as reinforcing the need for support for Ukraine.

Leaders are expected to sign off on commitments to maintain existing levels of support for Ukraine at a minimum, as well as for Nato to take over handling the co-ordination of that support. New Zealand is expected to make an announcement on further support, on top of its renewal of troop deployments to train Ukrainian forces until mid-2025.

Luxon will also chair the meeting of the Indo-Pacific 4 – Australia, Japan, Korea and New Zealand. Zelenskyy is expected to attend that meeting.

The Indo Pacific 4 have only been invited to attend the summit for the last three years.

Ahead of the summit, Nato Secretary General Jens Stoltenberg said Ukraine had showed security was not regional but global, and pointed to actions of Iran, North Korea and China in dealing with Russia.

“The closer that authoritarian actors align, the more important it is that we work closely with our friends in the Indo-Pacific.”

He said the focus would be on flagship projects on Ukraine, cyber, and new technologies.

Claire Trevett is the NZ Herald’s political editor, and is in Washington DC to cover PM Christopher Luxon’s visit and Nato Summit.