(CNN) -- Canadian Prime Minister Stephen Harper on Wednesday said a report on the Keystone XL pipeline was "pretty definitive" in its assessment that it would not affect climate change, an issue President Barack Obama says must be part of the discussion.
The comments by the two leaders came at a news conference following a summit of the leaders of North America, which brought together Harper, Obama and Mexican President Enrique Pena Nieto in Toluca, Mexico.
The meeting between the two leaders came as the State Department is reviewing whether the proposed pipeline that would carry crude oil from Canada to refineries in Texas would be beneficial to the country.
Obama said the State Department was reviewing the report and that it would be followed by a comment period.
"We'll make a decision at that point," he said.
Harper and Obama, who have a good relationship, are deeply divided over the issue. And the division was on display at the summit as the two discussed the differences during the news conference.
"My views in favor of the project are very well-known. His views on the process are also very well-known," Harper said.
Obama reiterated his position that any impact on climate change caused by the pipeline must be considered.
"It has to be part of the discussion," he said.
The countering statements between Harper and Obama came the same day a Nebraska state judge voided Gov. Dave Heineman's approval of the Keystone XL pipeline route.
Lancaster County Judge Stephanie Stacy on Wednesday issued a ruling saying the decision on where the oil pipeline should be located needed to be made by the state's Public Service Commission.
Stacy called the current law giving the governor approval authority unconstitutional.
The decision can be appealed, but it is if upheld, it would likely delay work on the proposed pipeline.
A senior administration official said the decision may ultimately impact the project, but doesn't likely affect its review.
CNN's Chelsea J. Carter contributed to this report.