Why do some accents have such hard time pronouncing the "V"?

After years of observing and constantly listening to people from different cultures, I came under the conclusion that in those with no native, Indo-European language, they are going to have a very hard time pronouncing the "V" sound. For example, many people from Asia, Africa, and the middle East. For some reason I think "V" and "W" are very difficult sounds for others to pronounce. Typically black people from Africa can't pronounce the letter "v" because of their accent and this is a common observation that there is nothing mean spirited or racist in this post, Just an observation.<br><br>So yes, why do some people with foreign accents have a hard time pronouncing the "V" sound?