Experienced centre Roberts will skipper Robin McBryde’s 32-man party next month for the clashes with the Pacific Islanders.
Wales face Tonga at Auckland’s Eden Park on June 16 as part of a Pasifika Challenge double header with New Zealand and Samoa. They will then face Samoa themselves in Apia the following weekend.
Roberts said: “It’s a huge honour, not just for me but for my family. I’d like to thank Robin McBryde and Shaun Edwards for giving me the opportunity.
“More importantly, I’m excited for the young players in the squad. It’s an opportunity for them to experience the Test environment and know what it’s about at that level.
“I think a lot of the senior players in the group who maybe haven’t had the chance to play in the last couple of years now have the chance to step up and lead this team.”
With 91 Wales caps and two British & Irish Lions tours on his career CV, Roberts’ experience will be vital this summer.
The Harlequins midielder will help guide the 13 uncapped players in McBryde’s squad.
Keelan Giles, Steffan Evans, Ollie Griffiths and Rhun Williams are just four of a number of fresh faces who will be part of a Wales tour for the first time.
Roberts added: “I’m excited for everyone involved. It will be two tough games, certainly the match at Eden Park will be pretty special.
“To play before the All Blacks will be special and we know from the past how tough Samoa are. It will be two tough games without our British Lions and I can’t wait to get stuck in.
“I was as disappointed as any player not to make the Lions squad. I missed out and I moped around for a day, but then you dust yourself off and get back to training hard and playing your best.
“That motivation will always be there, but the focus now is winning two games with Wales and preparing the team as best as possible.
“There is some great talent in Wales and with one eye on 2019 it’s about making sure these players develop as quickly as possible.”
