The Canadian Press-Harris Decima survey found 64 per cent of respondents felt the approach to relations was working and 58 per cent felt Harper was working hard on the relationship between the two countries.
Harris Decima senior vice-president Doug Anderson says support for Harper's efforts goes beyond partisan politics.
"Right now, the proportion of Canadians who would vote for some party other than the Conservatives is far higher than the proportion who would," Anderson said.
"There's only 18 per cent of the population who feel that anything that Prime Minister Harper has done has made the situation worse between the two countries. There's more people — 24 per cent — who say that his actions and decisions have improved relations," he added.
And the survey respondents indicated about one in five feel U.S. President Barack Obama's decisions and actions have improved relations between the North American neighbours.
Fifty-three per cent of those surveyed said Obama has worked hard to improve relations.
But 38 per cent felt his decisions had a negative impact on the Canadian economy.
"That is greater than the proportion who would criticize Obama's performance overall," Anderson said.
The survey results are based on interviews in late June with just over 1000 Canadians and have a margin of error of 3.1 per cent, 19 times out of 20.
The survey also indicates Canadians prefer Obama to Republican Mitt Romney by an almost a seven to one margin.
Nationally, 68 per cent would vote for Obama if they had a vote in the upcoming presidential election, while 10 per cent would vote for Romney.
Obama is the preferred choice of a majority of respondents across all regions and demographic groups, Anderson said.
"While it should be cautioned that Canadian opinion of Mitt Romney is undoubtedly much softer than for the incumbent President Obama, it is clear that Canadians remain relatively supportive of the current U.S. president," Anderson said.
The survey indicated Canadian support for Obama has grown since Harris Decima last polled on the subject last October.
The poll findings appear to contradict an article last month in the online edition of Foreign Affairs that said Obama had "lost Canada."
The article cited a litany of wrongs that its authors pin on Obama, including the delay in the Keystone XL pipeline, protectionist Buy American provisions, even disrespect for Canadian military contributions in Libya and Afghanistan.
As a result, authors Derek Burney, a former Canadian diplomatic heavyweight and one-time ambassador to the U.S., and Fen Hampson, a Carleton University foreign policy expert, concluded the U.S. has jilted Canada, leaving relations at "their lowest point in decades."
The article also noted how Harper had declared it an economic imperative to bolster trade with China, India, South Korea and other Asian countries and "sell our energy to people who want to buy our energy."