"Every day it becomes more evident for our nation to achieve true energy security we must engage our stable and reliable neighbours — Canada in particular," Gen. Jim Jones, who left the administration in 2010, told a conference call hosted by the American Petroleum Institute, a major pipeline proponent.
"The country can't afford to pass up the opportunity for reliable supply from a close ally and neighbour, which would leave us less vulnerable .... This is the right time to show our neighbours to the north that we are partners with them."
The $7 billion pipeline will help end American dependence on oil from often hostile OPEC regimes in addition to creating thousands of jobs stateside, he said.
"Energy may not be the only way out of our current economic difficulties, but it is a huge way," he said, adding the pipeline can help the U.S. "dig ourselves out of the economic situation we find ourselves in."
Jones's show of support came as Keystone remained in the spotlight on Capitol Hill, with Republicans in the House of Representatives insisting that their payroll tax cut bill will include a measure aimed at forcing approval of the pipeline within 60 days — well before next year's presidential election.
"I guarantee that the Keystone pipeline will be in there when it goes back to the United States Senate," John Boehner, House majority leader, said as he emerged from a closed-door meeting with his colleagues.
Mitch McConnell, the Republican Senate minority leader, also said he won't back the extension of payroll tax cuts unless the legislation includes the Keystone XL measure.
Obama and most congressional Democrats oppose any move to speed up Keystone XL approval, with the White House suggesting this week the president could veto the bill if the pipeline measure isn't removed. The Canadian project, indeed, represents the biggest obstacle to a bipartisan pact in the days to come on extending payroll tax cuts for hard-hit Americans.
Last month, the U.S. State Department deferred a decision on Keystone until after the 2012 election so it could undertake a further environmental analysis on an alternative route around a crucial aquifer in Nebraska.
The move spurred howls of protest from Republicans who accused the Obama administration of making a political decision aimed at shielding the president from a backlash by his liberal base next November. Sources familiar with the State Department decision said it resulted from pressure by senior White House advisers.
The pipeline would carry millions of barrels of Alberta oilsands crude through six U.S. states to Gulf Coast refineries. Proponents say the pipeline will create thousands of jobs and end American dependence on Middle East oil, while opponents say the pipeline is an environmental disaster waiting to happen.
Jones said he has long believed energy is a national security issue, and told Obama as he left office in November 2010 that he had an opportunity to go down in history as "the energy president."
He hasn't spoken to anyone in the administration since then about his opinions on Keystone, but added "my former colleagues know exactly how I feel about where we need to go in regards to energy."
Approval of the pipeline will show the world that America is on the cutting edge of energy policy, Jones said.
"Apart from this important project, there's a great need in the United States to ensure its economic future but also position itself as a global leader on energy and energy policy," he said.
If lawmakers cannot reach an agreement on approving the pipeline, he added, then "we are definitely in a period of decline in terms of our global leadership and in terms of our ability to compete in the 21st century."