JOHANNESBURG (AP) — The top United States diplomat to Africa says perhaps it's time to take the deadly separatist crisis in Cameroon to an "international forum."

An exasperated Tibor Nagy told reporters on Tuesday that "my heart breaks for Cameroon ... I just don't understand why this crisis goes on and on and on."

Some half a million people have been displaced as Cameroon's government battles an Anglophone separatist movement in the largely French-speaking country. Weary residents in the middle have pleaded for peace.

Nagy, the U.S. assistant secretary of state for Africa, called for "open, unlimited national dialogue."

Cameroon's government in a strongly worded statement last week criticized Nagy's earlier comments on the Anglophone crisis, accusing him of misunderstanding the situation and interfering in the West African country's internal affairs.