The United Nations has appointed a Norwegian national as an interim resident coordinator in Myanmar and resident representative for the UN Development Program in the country.

The UN said in a statement Tuesday that Knut Ostby, who has served as a UN resident coordinator for more than 11 years, replaces Renata Lok-Dessallien in his new role.

The announcement comes after more than 600,000 minority Rohingya Muslims have been driven out from Myanmar since late August amid a brutal crackdown by military security forces in northern Rakhine state.

Lok-Dessalien has been criticized both by the UN and other international organizations for allegedly not effectively handling the human rights concerns in Rakhine.