He went on to work in several capacities at the UN Headquarters including serving as the Under-Secretary-General for peacekeeping between March 1992 and December 1996.
Ia kemudian memegang beberapa jabatan di Markas PBB, termasuk Wakil Sekretaris Jenderal bidang penjagaan perdamaian sejak Maret 1992 sampai Desember 1996.