UNITED NATIONS — U.N. Secretary-General Ban Ki-moon says he’s disappointed by many world leaders who care more about retaining power than improving the lives of their people — and can’t understand why Syria is being held hostage to “the destiny” of one man, President Bashar Assad.

Nearing the end of his 10 years at the helm of the United Nations, Ban spoke frankly about the state of the world and his successes, failures and frustrations as U.N. chief in a wide-ranging interview with The Associated Press.

Ban is the public face of the organization but he said that in private leaders see a very different and much tougher side to him.

“People say I have been quiet, and I have not been speaking out about human rights, but I can tell you I have been speaking out (more) than any of the Western leaders” who “are very cautious,” he said. “You have not seen people as fearlessly speaking out as myself.”

Ban also spoke candidly about his frustration at the way the U.N. operates.

It’s unrealistic to expect any secretary-general “to be some almost almighty person,” he said, because the world body’s member states make decisions and the U.N. chief implements them — rather than implementing their own initiatives and policies, he said.

The U.N. could be far more efficient and effective if there were “some reasonable decision-making process” — not one that requires consensus on many issues before the General Assembly and statements by the Security Council, Ban said. This gives one country the power to block something all other nations agree on, or to water it down.

“Is it fair? Is it reasonable in the 21st century when you have 193 member states?” Ban said.

As an example, human rights groups have criticized the declaration set to be adopted at the U.N. summit on refugees and migrants on Monday, ahead of the General Assembly’s annual gathering of world leaders, because it was watered down to reach consensus. The result was the elimination of Ban’s proposal to resettle 10 percent of the world’s refugees annually.