Prime Minister John Key is "fascinated, almost more than worried" about the US presidential election and questions whether Donald Trump would carry out anti-trade measures he has signalled.
The Republican candidate and Democratic rival Hillary Clinton are targeting swing states including Ohio, Pennsylvania and New Hampshire with just two days of campaigning to go.
Latest polls show Mrs Clinton still holds advantages in critical states, but her lead has narrowed.
Mr Key said the election process was is going to end up quite "unsatisifying" for the average American.
"I don't think they're voting for candidates they particularly love on either side," he told Morning Report.
"You've had a discourse going through the US public which is quite negative and ugly.
"I know you always get that in election campaigns but this time it feels a lot more heightened than normal."
image:85045:full] Hillary Clinton and Donald Trump during an election debate.
Mr Key said Mr Trump's "negative steps around trade" would not be good for TPP and globalisation - but the question was how many of them he would carry out.
New Zealand and US economists have predicted a hit to the economy of both countries in the event of a Donald Trump presidency.
The Institute of Economic Research said a Trump administration would have a significant negative effect on the US economy and a destabilising impact on New Zealand businesses and ASB Bank said growth in New Zealand could get "trumpled".
Their concerns echo those raised by 370 economists, who have signed an open letter to voters in the United States urging them not to vote for Mr Trump.
But Mr Key questioned whether a Trump government would put the tariffs and other trade measures in place.
For example, the Republican candidate's pledge of a 45 percent tariff on goods from China would put up prices significantly for the average American.
"The Economist wrote a story saying that would be the single biggest reduction in income for the average American that they'd seen basically in a generation. So is he really going to carry all those things out?"
This election was a contrast to the more generous atmosphere at the time Barack Obama was first elected president, he said.