BERLIN (AP) — South Sudan is "on the brink of an all-out ethnic civil war which could destabilize the entire region," the head of a team of U.N. human rights investigators told the U.N. Human Rights Council on Wednesday, describing a shattered country where children as young as 2 have been raped.

Yasmin Sooka addressed the council at a meeting requested by the United States as alarm grows about the rise of hate speech by South Sudanese officials and others as civil war grinds on.

Also Wednesday, South Sudan President Salva Kiir in a speech to parliament called for a national dialogue that would attempt to redefine the country's national identity. Kiir again called for a cease-fire in the civil war but offered few details on how it would work with multiple opposition groups across the country.

Kiir also urged an end to expressions of ethnic hatred. "I am calling upon all of you to forgive one another," he said.

Tens of thousands have been killed in fighting in South Sudan, and more than a million people have fled the East African country. Sooka said thousands of women have been raped. The economy has been crushed; Sooka said it has the world's highest inflation rate, at more than 800 percent in October.

The recent visit by the U.N. team of investigators found indications that "a steady process of ethnic cleansing is already underway in some parts of the country," Sooka said. She said fighting is expected to "begin in earnest" now that the dry season has arrived in South Sudan.

Zeid Ra'ad al-Hussein, the U.N. high commissioner for human rights, urged the council to call on South Sudan's leaders to refrain from incitement to violence and ethnic hatred.

Zeid said that "there may still be some space for consequential action to pull the country back from a worst-case scenario," noting that when local leaders intervened recently to halt hate speech, threats of violence decreased.

South Sudan's government remains under international pressure to quickly allow the deployment of an additional 4,000 peacekeepers to help protect civilians.

Associated Press writer Justin Lynch in Koboko, Uganda, contributed.