John Key flew across the world for talks with the US President, but his meeting was slashed to only 30 minutes.

The Oval Office chinwag fell victim to America's worsening debt crisis: Barack Obama could spare only half of the hour he had planned, because he had to deal with collapsing financial negotiations. From August 2, the United States will be unable to meet interest payments on its US $14.3 trillion sovereign debt: Obama must either default on interest payments, cut spending in defence and healthcare, or obtain the agreement of Congress to raise the ceiling on the amount he can borrow.

The President has summoned congressional leaders to the White House today in a bid to find a solution before the markets open on Monday.

But Key said he was delighted with the visit.

"This is a tough time for him," the Prime Minister told the Herald on Sunday. "United States is 10 days away from potentially defaulting.

"No one is arguing that's going to happen but he still made time for us in amongst all of that. And if you consider it in that perspective, it was very successful "

Key called himself the "lucky Prime Minister" to have arrived in Washington at a time when the relationship had "come of age" after the 25-year anti-nuclear rift.

Speaking to reporters after the meeting, he shared credit for the improved relations with previous leaders.

"It's a lot of successive administrations and Prime Ministers if we are genuinely honest. They have all put in the hard yards."

The United States recognised that New Zealand was not changing its anti-nuclear policies, "and we recognise on their side that they have their concerns about the way they look at the world."

The nuclear issue could be parked. The maturity and breadth of the relationship meant it was not the defining issue. Trade was the major issue on their agenda and Obama confirmed he wanted a broad outline of the nine-country Trans Pacific Partnership ready for the Apec summit in Honolulu in November.

The meeting wasn't all heavy-duty policy.

The pair asked about each other's children and Obama had asked if Key's son Max was still mad-keen on baseball, something he had mentioned in the past.

Obama was also envious that Key would be taking a few days off in Hawaii, where the two men both have homes.

Key bought a new gold tie but did not buy a new suit for the meeting. He said he wore the same suit he had worn to the wedding of Prince William and Catherine Middleton in May - it has greenstone as part of the weave.

Key gave Obama a mere gifted by Ngai Tahu on behalf of New Zealand.

Obama gave Key one of the two "Sting" swords made for the character Bilbo Baggins in The Hobbit movie under production in New Zealand.

Key said Obama invited himself to New Zealand but that would not be possible until after the next presidential election, at least 2013.

Obama got Key's name wrong, twice calling him Mr "Keys".

Key is used to it: "To be honest it's the first time he's ever used my surname; he always called me John so, hey, I'm not bothered."

Key staff member wilts in the heat

John Key's chief press secretary succumbed to heat stroke in the dangerously high temperatures that plagued Washington during the Prime Minister's visit.

The White House's doctor was dispatched to the official guest house, Blair House, to treat press secretary Kevin Taylor. He had fallen ill after returning from Arlington Cemetery.

The PM's official party stood in the beating heat for up to 20 minutes while Key laid a wreath at the Tomb of the Unknowns.

The official high in the capital was 43C, but police assigned to Key put the temperature at Arlington at the time at 47C.

After resting, Taylor recovered in time to make yesterday's meeting at the Oval Office.

White House press secretary Jay Carney said: "Washington is bad but it's almost never this bad. It's dangerously high."

Another 300 people were taken to hospital with heat-related difficulties the day Taylor fell ill, The Washington Post reported.

Obama told Key after the meeting: "This is a warmer welcome than you perhaps had expected".