The conservative prime ministers of Canada and Australia said economic concerns were more important than acting on climate change.
Both have faced criticism over their climate policies after US President Barack Obama last week unveiled major regulations to reduce greenhouse-gas emissions in the United States.
"It's not that we don't seek to deal with climate change, but we seek to deal with it in a way that will protect and enhance our ability to create jobs and growth and not destroy jobs and growth in our country," Canadian Prime Minister Stephen Harper said.
"And, frankly, every single country in the world, this is their position ... We are just a little more frank about that."
Australian Prime Minister Tony Abbott, who is in Canada as part of a trade mission to North America, acknowledged that climate change was "a significant problem".
But he added: "We should do what we reasonably can to limit emissions and avoid climate change, man-made climate change, but we shouldn't clobber the economy."