From what I can tell from searching around this is a fake not actually connected to the UN. It seems to have been created for self-promotion by this "Jayme Illien" guy whose "Happytalism" thing it promotes. The website is registered by him (specifically the "Illien Global Public Benefit Corporation"):
Here's his Wikipedia article that I think he also wrote about himself, which has since been deleted:
It has all sorts of self-serving bullshit that you can tell he wrote and is obviously sketchy as fuck. For example the first thing I notice in the box is "Born: Adam (named by Saint Mother Teresa at orphanage) Calcutta, India" - "Born" is just supposed to list date and place of birth, not his name or supposed connection to Mother Teresa. It said he was the "CEO" of the UNNWO project - UN projects do not have CEOs because they are not companies. It says he founded DBFX and seems to think it was a company rather than the trading platform for Deutsche Bank, then switches to talking about FXCM instead which obviously he had nothing to do with either. Similarly it looks like he edited the UN International Day of Happiness wikipedia page, falsely claiming to have created it. (This also got some other articles to list him as the creator because they copied the Wikipedia article.) It looks like the "Official website" link used to go to one of his websites before someone edited it to go to the actual official website, but they haven't fixed how it says he created it:
Looks like he edited the wikipedia pages for some other articles like the one for DBFX too. The only "news" article I can find about the UNNWO project is this one from "PR Newswire", because he issued a press release so he could pass it off as a news article:
There doesn't seem to be any actual news article or anything on the UN website about it, just an elaborate effort by this one guy. Maybe he uses it to scam people, or maybe he's one of those pathological liars who needs to convince the world he's the most amazing person ever.