BERLIN (AP) — German Chancellor Angela Merkel is expressing concern about the human rights situation in Libya and Sudan while calling for an improved approach to the factors that force people to migrate.

Merkel said before a meeting Monday with the head of the U.N. refugee agency that “the challenges (of migration) continue to be gigantic.”

U.N. High Commissioner for Refugees Filippo Grandi said the escalation of fighting in Libya made it difficult to work in the refugee camps there. He thanked Germany for its support of migrants in Libya and elsewhere.

Separately, Merkel talked to Egyptian President Abdel-Fattah el-Sissi on the phone about the political instability in Libya and Sudan. She says Germany supports the Sudanese opposition’s demand for the military government to hand power over to a civilian administration.