ADDIS ABABA, Ethiopia - Visiting sub-Saharan Africa for the first time since taking office, Secretary of State John Kerry on Saturday remained focused largely on the Middle East, particularly Egypt, whose cratering economy and political problems are dimming hopes it can play a major role in fostering any new peace plan between Israel and the Palestinians.

Kerry sandwiched a day of celebratory meetings at the African Union's 50th anniversary summit in Ethiopia between peacemaking efforts in Israel, the West Bank, and Jordan. He will return to the Mideast on Sunday, then go to Paris to compare notes on Syria with Russian Foreign Minister Sergei Lavrov.

Kerry sat down with Egyptian President Mohamed Morsi to discuss Egypt's slow-moving efforts to comply with economic reforms crucial to securing international loans and investment.

He thanked the Muslim Brotherhood-backed Egyptian leader for his country's cooperation in inaugurating new peace talks between Israel and the Palestinians, although Egypt's role is far less visible under Morsi's Islamic government than when the secular autocrat Hosni Mubarak was in power.

Kerry's meetings at the summit began Saturday with a warning to close U.S. partner Nigeria that it must not condone human-rights violations by its own forces fighting the Boko Haram militants in the country's north.

"Boko Haram is a terrorist organization . . . and so we defend the right completely of the government of Nigeria to defend itself and to fight back against terrorists," Kerry said.

"That said, I have raised the issue of human rights with the government, with the foreign minister; we have talked directly about the imperative of Nigerian troops adhering to the highest standard and not themselves engaging in human-rights violations and atrocities," Kerry said at a brief news conference.

Boko Haram extremists are accused of terrorist attacks primarily against Nigerian police and Christian civilians and are accused of hundreds of killings.

Kerry briefly saw Nigerian President Goodluck Jonathan on the sidelines of the gathering. Oil-rich Nigeria is a key U.S. partner on and off the African continent, but the relationship is often troubled. Kerry issued a statement May 17 accusing Africa's most populous country of "gross human rights violations" following Jonathan's declaration of a state of emergency in three Nigerian states, but he did not repeat that language Saturday.