President Trump signed executive orders on Tuesday effectively reviving the controversial Keystone XL and Dakota Access pipelines, as a major builder said it will reapply to build one of the projects which had been stalled by the Obama administration under pressure from environmental and other groups.

The president said the projects would be subject to a “renegotiation of the terms.” But he made clear the government was resuming consideration for both pipelines, describing them as a potential boon to construction workers.

“We’re going to put a lot of … steel workers back to work,” Trump said. “We’ll build our own pipelines, we will build our own pipes.”

Builder TransCanada said Tuesday afternoon it was "preparing the application" for the Keystone XL pipeline.

"We appreciate the President of the United States inviting us to re-apply for KXL," TransCanada spokesman Terry Cunha said in a statement.

"KXL creates thousands of well-paying construction jobs and would generate tens of millions of dollars in annual property taxes to counties along the route as well as more than $3 billion to the U.S. GDP," Cunha added.

According to White House Press Secretary Sean Spicer, Trump directed agencies to approve it without delay -- and told agencies to expedite reviews and approvals for the remaining parts of the Dakota project.

“There’s an energy revolution that’s going to happen in this country,” he said.

The president also signed three other orders related to pipeline construction, including one expediting the environmental permitting process for infrastructure projects and one directing the Commerce Department to maximize the use of U.S. steel.

Looking ahead, Trump also announced he planned to nominate a justice for the Supreme Court next week, moving swiftly to try to fill the seat left vacant by the death of Justice Antonin Scalia. The president was summoning top senators to the White House later Tuesday to discuss his upcoming nomination.

The moves on the pipelines had been widely expected, as Trump last year blasted his predecessor for effectively blocking the projects.

Republican allies hailed Tuesday’s orders, with House Speaker Paul Ryan saying in a statement, “It’s about time.”

North Dakota Rep. Kevin Cramer said: “Today’s executive orders affirm President Trump’s respect for the rule of law and his support for responsible infrastructure development, energy production and job creation.”

Former President Obama stopped the proposed Keystone XL pipeline in late 2015, declaring it would have undercut U.S. efforts to clinch a global climate change deal that was a centerpiece of his environmental legacy. The pipeline would run from Canada to Nebraska where it would connect to existing lines running to U.S. refineries on the Gulf Coast. The U.S. government needs to approve the pipeline because it would cross the nation's northern border.

Separately, late last year, the Army Corps of Engineers declined to allow construction of the Dakota Access pipeline under Lake Oahe, saying alternative routes needed to be considered. The Standing Rock Sioux tribe and its supporters say the project threatens drinking water and Native American sites, though Energy Transfer Partners, the company that wants to build the pipeline, disputes that and says the pipeline will be safe.

The pipeline is to carry North Dakota oil through South Dakota and Iowa to a shipping point in Illinois. The project had been the subject of fierce protests until the Army Corps of Engineers stepped in.

The moves are likely to spark a new fight with environmentalists. Even before Trump’s orders were official, Sierra Club Executive Director Michael Brune put out a statement blasting what he called the “dangerous” decision.

“The Keystone pipeline was rejected because it was not in the country’s interest, and the environmental review of the Dakota Access Pipeline was ordered because of the threats it poses to the Standing Rock Sioux. Nothing has changed. These pipelines were a bad idea then and they’re a bad idea now,” he said.

The moves come as Trump makes the economy and jobs the centerpiece of his administration’s first week in office.

He met Tuesday morning with representatives from the auto industry including GM and Ford, after meeting a day earlier, separately, with business and union leaders.

The pipelines were among the few issues that put the Obama administration at odds with labor unions, some of whom have voiced hope the Trump administration can work with them to promote job creation. Trump said Tuesday during his meeting with auto industry bosses that he considers himself an environmentalist, but called current regulations "out of control."

The pipeline orders follow earlier executive actions covering everything from trade to ObamaCare.

Trump on Monday signed measures withdrawing the U.S. from the Trans-Pacific Partnership trade deal, and instituting a hiring freeze for most of the federal government. He also ordered federal agencies on his first day in office to ease the regulatory burden of the Affordable Care Act.

Fox News’ John Roberts and The Associated Press contributed to this report.