Nigerian envoy commends un in checking terrorism humanitarian crisis

Here is a rewritten version of the sentence in a more formal and polished tone:

"The Nigerian Envoy Commends the United Nations for its Efforts in Addressing Terrorism and Humanitarian Crises."

Here is a possible expansion of the sentence:

"The Nigerian Envoy has expressed appreciation to the United Nations for its tireless efforts in addressing the scourge of terrorism and humanitarian crises that have plagued the world. The Envoy commended the UN for its commitment to promoting peace, stability, and human rights, and for providing critical support to affected communities. The Envoy also acknowledged the UN's role in mobilizing international cooperation and resources to address these complex challenges, and expressed hope that the organization's efforts would continue to yield positive results."