UN environmental chief Erik Solheim announced his resignation on the UN Environment Programme's (UNEP) website after receiving a report on Saturday published by the UN's auditing watchdog.
The disgraced Norwegian diplomat will step down on Thursday after the report revealed that he had spent roughly $500,000 on flights and accommodation over a period of just 22 months, in addition to spending 80 percent of his time away from the organisation's Nairobi office, according to The Guardian.
Solheim's actions were a "reputation risk" for the UN agency charged with tackling climate change, in addition to draining vital budgets from the UNEP.
"It is my most sincere hope that this proves to be in the best interest of UN Environment and the wider UN," Mr. Solheim said in his statement, adding that "we can be immensely proud of our accomplishments and the momentum for action we have created".
"I will remain a committed friend of UN Environment and to all the wonderful individuals and dedicated professionals with whom I have had the privilege to serve."
The UNEP has appointed Ms. Joyce Msuya of Tanzania as acting executive director until Secretary-General António Guterres can recruit a successor to Mr. Solheim, a UN statement said.
"The secretary-general is grateful for Mr. Solheim's service and recognizes he's been a leading voice in bringing the world's attention to critical environmental challenges," UN spokesman Stephane Dujarric said.
"The secretary-general is pleased to see that UNEP is committed to implementing the recommendations… on the travel office" made by the U.N. watchdog, the Office of Internal Oversight Services stated.