ate ▁UN OP S ▁often ▁works ▁in ▁post - dis aster ▁and ▁peace ▁and ▁security ▁settings , ▁developing ▁countries ▁and ▁econom ies ▁in ▁transition . ▁Form er ▁UN ▁Secretary - General ▁K of i ▁Ann an ▁designated ▁UN OP S ▁as ▁the ▁lead ▁United ▁Nations ▁entity ▁for ▁complex ▁infrastr ucture ▁projects ▁in ▁peace keep ing ▁settings . ▁ ▁In ▁December ▁ 2 0 1 0 , ▁the ▁United ▁Nations ▁General ▁Assembly ▁re aff ir med ▁UN OP S ▁mand ate ▁" as ▁a ▁central ▁resource ▁for ▁the ▁UN ▁system ▁in ▁proc ure ment ▁and ▁contract s ▁management ▁as ▁well ▁as ▁in ▁civil ▁works ▁and ▁physical ▁infrastr ucture ▁development , ▁including ▁the ▁related ▁capacity ▁development ▁activities ." ▁ ▁At ▁the ▁official ▁opening ▁of ▁the ▁UN OP S ▁headquarters ▁in ▁C open hagen ▁ ▁in ▁May ▁ 2 0 0 9 , ▁former ▁UN ▁Secretary - General ▁Ban ▁Ki - mo on ▁described ▁UN OP S ▁as ▁a ▁ ▁member ▁of ▁the ▁UN ▁family ▁with ▁a ▁" crit ical ▁role ▁in ▁providing ▁management ▁services ▁for ▁our ▁life - s aving ▁peace building , ▁human itar ian ▁and ▁development ▁operations ▁[ … ] ▁setting ▁countries ▁on ▁course ▁to ▁a ▁more ▁stable ▁future ▁by ▁helping ▁them ▁to ▁build ▁roads , ▁schools ▁and ▁clin ics , ▁to ▁remove ▁land min es , ▁to ▁prepare ▁for ▁dem ocr atic ▁elections , ▁and ▁much ▁else ". ▁ ▁Current ▁UN ▁Secretary - General ▁Ant ón io ▁G uter res ▁highlight ed ▁UN OP S ▁important ▁role ▁in ▁providing ▁meaning ful ▁expert