Permanent Secretary for Foreign Affairs Bilahari Kausikan, 58, will retire from the Administrative Service next month after 31 years of service in the public sector, said the Public Service Division(PSD) in a statement on Thursday.

Replacing him on June 1 is Brigadier-General (NS) Chee Wee Kiong, 49, who is currently Second Permanent Secretary at the Ministry of Foreign Affairs (MFA).

Mr Kausikan, who will then be Ambassador-at-large, "steered the Singapore Foreign Service ably with his pragmatic leadership in managing Singapore's foreign relations in an increasingly complex and uncertain international environment", PSD said.

BG(NS) Chee, a former Singapore Armed Forces Overseas Scholarship holder, was Director of the Security and Intelligence Division at the Defence Ministry from 2005 until his appointment as MFA's Second Permanent Secretary in 2010.