GENEVA — Zeid Ra’ad al-Hussein began his tenure on Monday as the United Nations human rights chief with a strongly worded statement in which he condemned Islamic extremism and urged international action to end conflicts in Syria and Iraq.

In his first speech to the United Nations Human Rights Council in Geneva, Mr. Zeid, a Jordanian prince who has dispensed with his royal title as incompatible with his new post, identified the conflicts in Syria and Iraq as “the immediate and urgent priority of the international community.”

Pledging to be “firm, yet always fair, critical of states where necessary,” Mr. Zeid, the first Muslim to assume the post as the United Nations high commissioner for human rights, delivered a 40-minute statement. He called for the protection of civilians by all parties to “the deplorable conflict” in Ukraine; praised investigations into human rights abuses in North Korea and Sri Lanka; highlighted the “chain of human rights violations” committed by Australia in its treatment of migrants; and voiced concern about the United States’ detention of unaccompanied child migrants.