The 16-year war in Afghanistan is not going to end any time soon, former CIA Director David Petraeus said Friday in an interview with PBS NewsHour’s Judy Woodruff.

“This is a generational struggle. This is not something that is going to be won in a few years. We’re not going to take a hill, plant a flag and go home to a victory parade,” said Petraeus, who also oversaw U.S. forces in Afghanistan and Iraq during his military career. He is now a partner at KKR global investment firm.

“You know, we’ve been in Korea for 65-plus years, because there’s an important national interest for that. We were in Europe for a very long period of time,” he said. “We’re still there, of course, and actually with a renewed interest now given Russia’s aggressive actions.”

When Woodruff asked if he thought if the U.S. would need to stay in Afghanistan for 60 more years, he said he doesn’t think the U.S. involvement will last that long. But “I think we should not approach this as a year-on-year mission,” he said, noting that kind of instability gives Afghan leaders “the jitters.”

The current U.S. commander in Afghanistan, Gen. John Nicholson, has recommended sending 3,000 to 5,000 more troops to the 8,400 already there. Petraeus called the possible increase in forces “heartening” and “sustainable.”

Watch Woodruff’s full interview with David Petraeus on Friday’s broadcast of PBS NewsHour.