Is there an argument to force UTF8 in igraph funct

Question

I am trying to use an adjacency matrix that has labels in UTF-8. Is there a way to make sure iGraph functions use UTF8, something along the line of "encoding = "UTF8""? This is to avoid the following result (French text on a japanese system shows kanji instead of french diacritics). Thanks for any pointers.

> m1 <- graph_from_adjacency_matrix(m, mode = "directed", weighted = TRUE)
> m1

> IGRAPH 7a99453 DNW- 391 1454 -- 
+ attr: name (v/c), weight (e/n)
+ edges from 7a99453 (vertex names):
 [1] Accept     ->Accepter    Acknowledge->Appr馗ier   Acknowledge->Confirmer   Acknowledge->Conscient  
 [5] Acknowledge->Consid駻er  Acknowledge->Constater   Acknowledge->Convenir    Acknowledge->Donner   
+ ... omitted several edges

As per requested:

R version 3.3.3 (2017-03-06) Platform: x86_64-w64-mingw32/x64 (64-bit) Running under: Windows 7 x64 (build 7601) Service Pack 1

locale: [1] LC_COLLATE=French_France.1252 LC_CTYPE=French_France.1252 LC_MONETARY=French_France.1252 [4] LC_NUMERIC=C LC_TIME=French_France.1252

Actually, this may not be an issue with igraph, but with RStudio, since I just realised that although my tables are properly displayed with the View() command, if I just call them in the console, the French diacritics are displayed with Japanese kanji. In any cases, igraph also does this.