I think the UN onlye meets in New York. But there will be UN organisations and conferences in Brussels for sure.
weekly
At present day Waterloo, Belgium.
New York
It is a pleasure to meet him: Es un gusto conocerlo.
Un gusto means: a pleasure (as in: It's a pleasure to meet you)
Pleased to meet you = Es un gusto en conocerte
In it's Head Quarters
Luxembourg is located in Western Europe and is where Belgium, France, and Germany meet.
It meets from September to December.
The United Nations (UN).
September
"To meet" could be "reunir" or "conocer" in some circumstances. "un placer conocerte" is "a pleasure to meet you". "Vamos a reunir en la sala mañana" is "We will meet in the lounge tomorrow".