The former top trade official in the United States says the Democratic Party is split over trade.
Susan Schwab has told the APEC meeting in Singapore that the division leaves proposed free trade deals such as the Trans-Pacific Partnership, which includes New Zealand, up in the air.
The former US trade representative says the White House is reluctant to finish or recommit to trade deals because unions in the United States are now implacably opposed to free trade deals of any kind.
However, she says, American firms are increasingly anxious they will be shut out of free trade in the region.
President Barack Obama will be under pressure to make a statement on trade when he attends the APEC talks this week, Radio New Zealand's economic correspondent says.
However, Mr Obama's trip has been delayed by his attendance of the memorial service for those killed in the Fort Hood shootings in the US.
Mr Obama will now arrive in Singapore on Saturday evening, half-way through the two-day retreat for the region's 21 leaders.
That means he will not be able to attend a discussion on Friday including Mr Key, the leaders of the Philippines and Papua New Guinea and business leaders.
Mr Key was expected to use Friday's meeting with Mr Obama to push for America's recommitment to the eight-country Trans-Pacific Partnership free trade agreement, which includes the two countries.