“It has been a great honor to serve as President of this institution, and I want to thank all of you for your support to our mission of ending poverty in the world,” Kim wrote to World Bank staff in an email Monday morning.

Kim explained in his email that he will go on to join the private sector, where he said he will focus on “increasing infrastructure investments in developing countries.” According to Kim, the “key to bridging the massive development finance gap” is by working with the private sector.

Before joining the World Bank, Kim trained as a medical doctor and co-founded the nonprofit health care organization Partners in Health in 1987. He later went on to join the World Health Organization as an adviser, later rising in ranks at the World Bank in 2012.

Kim was was re-elected for a five-year term in 2017. He will leave his position at the World Bank by Feb. 1, before his term ends in 2022.

Sources close to the Bank told the Guardian that Kim’s decision to leave was a “personal decision.”