“The United States can’t fix" the Middle East, the top United States intelligence official said in an interview with the Washington Post published on Tuesday.

"The fundamental issues they have — the large population bulge of disaffected young males, ungoverned spaces, economic challenges and the availability of weapons — won’t go away for a long time,” said Director of National Intelligence James Clapper.

Clapper's pessimistic comments reflected the growing conviction within the Obama administration that protracted instability in the Middle East will be one of the legacies the president leaves to his successor.

The problem of the Middle East is extremely complex, and "I don't have an answer," Clapper acknowledged.

Iraq and Syria will be “in a perpetual state of suppression for a long time,” Clapper said, even if armed forces are able to root out Al-Qaida, the Islamic State and other extremist groups.

That doesn't seem about to happen, however. Syrian rebel groups have failed to clear the Islamic State from its self-proclaimed caliphate, despite the efforts of the U.S. and allied nations, and are locked in a stalemate with the regime of President Bashar al-Assad.

ISIS' territory may be slowly narrowed, but the fight against the jihadists and other extremists will last “decades,” Clapper said.

“They’ve lost a lot of territory [and] we’re killing a lot of their fighters," Clapper said. "We will retake Mosul, but it will take a long time and be very messy. I don’t see that happening in this administration.”

Clapper confirmed that he shared the pessimistic mood of President Barack Obama, who is nearing the end of his time in office. In recent weeks, the president has expressed his frustration with international partners.

Recent comments by the president suggest that he has come to regard some allies, such as Saudi Arabia, as “free riders” who are unwilling to pull their weight to manage chaos around the globe.

That said, Clapper does not believe the U.S. should or can back away from its role in the world, as suggested by presumptive Republican presidential nominee Donald Trump.

“I don’t think the U.S. can just leave town,” Clapper said. “Things happen around the world when U.S. leadership is absent. “We have to be present — to facilitate, broker and sometimes provide the force."