An alliance of First Nations leaders is preparing to fight proposed new pipelines in the courts and through unspecified direct action.

Native leaders from Canada and the United States were on Parliament Hill on Wednesday to underline opposition to both the Northern Gateway and Keystone XL pipelines.

The first would tie the Alberta oil sands to the West Coast, while the second would send bitumen to refineries on the American Gulf Coast.

Natural Resources Minister Joe Oliver said the federal government is consulting with First Nations, and is ready to hear their concerns.

"We're making every effort to respond to the concerns we have heard on the West Coast," he said after a caucus meeting.

'We have to wake up to the crazy decisions that this government's making to change the world in a negative way.'—Chief Reuben George, Tsleil-Waututh First Nation

"I've had quite a few conversations with aboriginal leaders and aboriginal people. And I've found those conversations very constructive. They want to do the best for their communities and we want to do the best for their communities as well. So I remain very hopeful."

Speaking to CBC News, Oliver said there was an "enormous economic benefit" at stake for First Nations.

"There is an opportunity to transform many aboriginal communities which have been suffering from high unemployment for far too long," he said. "There is an opportunity for jobs, for economic activity, for equity participation, and I would hope that when they see that there isn't an environmental risk that they would embrace these opportunities for their communities."

Oliver said the government supports peaceful protests as part of a democracy, but "we do expect people to live within the confines of the law."

Chiefs brush off federal appointment

Some of the chiefs brushed off the federal government's appointment this week of a special envoy to look at tensions between natives and the energy industry.

Vancouver-based lawyer Doug Eyford is to focus on energy infrastructure in Western Canada, but some native leaders say he has no credibility.

He is to examine First Nations concerns about the troubled Northern Gateway proposal, as well as the development of liquid natural gas plants, marine terminals and other energy infrastructure in British Columbia and Alberta.

He will discuss environmental protection, jobs and economic development, and First Nations rights to a share of the wealth from natural resources.

"He's going to be reaching out to find out more about their interests and their concerns and to look for ways that resource development can help improve the lives of aboriginals, create more employment, create more opportunities for communities," Oliver said.

Some native chiefs, however, said Eyford has already failed. Although he is also the federal government's chief negotiator on comprehensive land claims, they said he hasn't accomplished much on that file.

Chief Allan Adam of the Athabasca Chipewyan First Nation said natives are determined to block the pipelines.

"It's going to be a long, hot summer," he said at a news conference.

"We have a lot of issues at stake."

'We're going to stop these pipelines.'

Phil Lane Jr. of the American Yankton Sioux, said native groups south of the border will stand with their Canadian cousins.

"We're going to stop these pipelines on way or another," he said.

Chief Martin Louie of the Nadleh Whut'en First Nation in northern B.C., said the pipeline opponents will never back down.

"If we have to keep going to court, we'll keep doing that," he said.

He said the stakes are high and go beyond native issues.

"We're the ones that's going to save whatever we have left of this Earth," he said.

Aboriginal Affairs Minister Bernard Valcourt said he hopes no one resorts to violent confrontation.

"The rule of law applies," he said. "We are free to express our opinions. That's the genius of Canada but we do it within the respect of the rule of law. I think they will do that. I hope so."

Chief Reuben George of the Tsleil-Waututh First Nation on Vancouver Island said it's time to act against the federal government's resource development agenda.

"We, as a nation, have to wake up," he said. "We have to wake up to the crazy decisions that this government's making to change the world in a negative way."

Valcourt said it's not an either-or argument: "This is about responsible development. I think we have the genius in Canada to be able to develop our natural resources while protecting our environment."

With files from CBC News