Though the U.S. State Department on Friday issued an environmental review of the pipeline that raised no major objections, a final decision on the project will likely not come for months.
(Read more: Keystone XL oil pipeline clears significant hurdle)
The 1,179-mile pipeline would stretch from Canada to Nebraska, pumping roughly 1 million barrels of oil a day into the United States. But from land rights issues to the environmental impact, concerns over the pipeline have been paramount. Still, supporters of the project contend it would create thousands of jobs and reduce U.S. reliance oil imports from nations that are less friendly than Canada.
"Hey, we've got some obligation to friends in Canada that offer us their oil," Pickens said. "Hey listen, I'm surprised they haven't gone west into China with it. But they haven't."
In the past, Pickens has objected to how the U.S. imports oil through the Strait of Hormuz—a route that connects the several landlocked oil-producing nations in the Middle East with the Gulf of Oman and the Arabian Sea, which requires military safeguards. He noted there wouldn't be a need for forces to secure the Keystone pipeline, though.
"We don't have to have the 5th Fleet. We don't have to have any military protection for this," Pickens said of the Keystone pipeline.
Still, at just 1 million barrels of oil a day, Pickens said the Keystone pipeline wouldn't do much to impact gas or oil prices.
—By CNBC's Drew Sandholm with Reuters. Follow him on Twitter @DrewSandholm.