(Adds Canadian government reaction, paragraphs 7-8)
By Randall Palmer
OTTAWA, June 22 (Reuters) - If Canada's Liberal Party wins the October general election it will create a special cabinet committee to oversee damaged relations with the United States, Liberal leader Justin Trudeau said on Monday.
Trudeau, whose Liberals are in third place in most opinion polls, blamed Conservative Prime Minister Stephen Harper for souring ties with Barack Obama by lecturing the U.S. president in New York on the need to approve TransCanada Corp's Keystone XL oil pipeline.
Trudeau, son of late former Prime Minister Pierre Trudeau, said that until Canada implements a strong environmental policy, it is obvious that Washington will "delay, defer and eventually decline" approval of the Keystone pipeline from the Alberta oil sands to the U.S. Gulf Coast.
"In the end, it's not really about Keystone. It's about judgment," Trudeau said in a speech.
"It's about the narrowness that allowed one project in one industry - however large and important the project and industry - to define one of the most positive and prosperous bilateral relationships the world has ever known."
For six years, Obama has mulled whether to approve Keystone. He has said his decision would hinge in part on whether carbon emissions would rise.
Responding to Trudeau's remarks, the Conservative government's natural resources minister, Greg Rickford, referred to U.S. State Department findings that Keystone XL would be safer than shipping oil by rail and that it would not have significant adverse effects on the environment.
"The environmentally responsible choice is for Keystone XL to be approved. This is not a debate between Canada and the U.S., it's a debate between the President and the American people, who are supportive of the project," Rickford said.
Trudeau said that if elected prime minister he will dedicate one cabinet committee entirely to the U.S. relationship.
He pledged also to push for a North American agreement on clean energy and the environment. And he said as a first step to improving North American relations, he would lift the requirement for visas from Mexico.
Trudeau conceded that as a Liberal prime minister, his father did not have the best relations with then-President Richard Nixon, a Republican, nor did Conservative Prime Minister John Diefenbaker with Democratic President John F. Kennedy.
But he said it was hard to imagine any Canadian prime minister pulling the "fruitless stunt" of going to New York to try to "force publicly the hand of the president of the United States" over Keystone. (Reporting by Randall Palmer; Editing by Peter Galloway)