World leaders are paying tribute to Ethiopian Prime Minister Meles Zenawi, who died late Monday after more than 20 years in power.

In a statement Tuesday, United Nations chief Ban Ki-moon said Meles will be remembered for “exceptional leadership” on African issues and overseeing his country's economic growth.

U.S. President Barack Obama said Meles deserves recognition for his contributions to Ethiopia's development and his commitment to helping the country's poor.

Mr. Obama, in his statement, also said he is grateful for Meles' service for peace and security in Africa. That comment was echoed by the African Union, which noted the help Meles gave to Somalia's government and AU troops who are fighting militant group al-Shabab.

None of the statements made note of Meles' human rights record. Human Rights Watch said Tuesday that the late Ethiopian leader put economic development ahead of human rights. The group has frequently criticized Meles for oppressing political opponents and the media.

A rebel group in Ethiopia's Ogaden region, the ONLF, said Meles had caused “unimaginable suffering” to the Ogaden people, but suggested his death could lead to greater stability and peace.

Ethiopian officials say Meles died in a hospital outside Ethiopia from an infection, after suffering from a prolonged illness.

Speaking with VOA (Somali Service), government spokesman Bereket Simon declined to give further details.

“The prime minister had been sick for quite a while,” he said. “And he was attending medical support in, somewhere in, ah, abroad. And he had some chance in recuperating. But ultimately some infection happened to him and doctors couldn't control that infection.”

Bereket said the body is being returned to Ethiopia, and officials are making plans for the funeral.

He also confirmed that Meles' former deputy, Hailemariam Desalegn, is taking over as prime minister.

Bereket said there is “no worry” about Ethiopia's future. He said the country's leaders are united and the government is “strong as ever.”

“The policies, the strategies, that have enabled us to register massive growth are in place,” he said. “The party is strong as ever, government is as strong as ever, the leadership is as united as ever. So there is no worry. There is no worry at all.”

Meles and his EPRDF alliance ruled Ethiopia for more than 20 years after taking power in a 1991 coup.